Fix Style java code format and warnings

The code had many bad formating and syntax or API usage warnings,
as well as some unused methods or classes which are fixed with this
patch.

Pick-to: 6.2 5.15 6.1
Task-number: QTBUG-71590
Change-Id: Ib113a0dc05703afb5190ec880b27daf75274cb1e
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>

3 files changed, 346 insertions, 533 deletions

diff --git a/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java b/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java
index d6e0e6f129..f5c2a6c6ac 100644
--- a/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java
+++ b/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java
@@ -40,22 +40,6 @@
 
 package org.qtproject.qt.android;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.OutputStreamWriter;
-import java.lang.reflect.Field;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.json.JSONArray;
-import org.json.JSONException;
-import org.json.JSONObject;
-import org.xmlpull.v1.XmlPullParser;
-
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.ColorStateList;
@@ -67,9 +51,8 @@ import android.graphics.Bitmap.Config;
 import android.graphics.Canvas;
 import android.graphics.NinePatch;
 import android.graphics.Paint;
-import android.graphics.Rect;
-import android.graphics.RectF;
 import android.graphics.PorterDuff;
+import android.graphics.Rect;
 import android.graphics.drawable.AnimatedStateListDrawable;
 import android.graphics.drawable.AnimationDrawable;
 import android.graphics.drawable.BitmapDrawable;
@@ -86,7 +69,6 @@ import android.graphics.drawable.RotateDrawable;
 import android.graphics.drawable.ScaleDrawable;
 import android.graphics.drawable.StateListDrawable;
 import android.graphics.drawable.VectorDrawable;
-import android.os.Build;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.util.TypedValue;
@@ -94,15 +76,29 @@ import android.util.Xml;
 import android.view.ContextThemeWrapper;
 import android.view.inputmethod.EditorInfo;
 
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.xmlpull.v1.XmlPullParser;
 
-public class ExtractStyle {
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
 
-    native static int[] extractChunkInfo20(byte[] chunkData);
-    native static int[] extractNativeChunkInfo20(long nativeChunk);
+
+public class ExtractStyle {
 
     // This used to be retrieved from android.R.styleable.ViewDrawableStates field via reflection,
     // but since the access to that is restricted, we need to have hard-coded here.
-    final int[] viewDrawableStatesState = new int[] {
+    final int[] viewDrawableStatesState = new int[]{
             android.R.attr.state_focused,
             android.R.attr.state_window_focused,
             android.R.attr.state_enabled,
@@ -114,7 +110,6 @@ public class ExtractStyle {
             android.R.attr.state_drag_can_accept,
             android.R.attr.state_drag_hovered
     };
-
     final int[] EMPTY_STATE_SET = {};
     final int[] ENABLED_STATE_SET = {android.R.attr.state_enabled};
     final int[] FOCUSED_STATE_SET = {android.R.attr.state_focused};
@@ -127,10 +122,10 @@ public class ExtractStyle {
     final int[] FOCUSED_SELECTED_STATE_SET = stateSetUnion(FOCUSED_STATE_SET, SELECTED_STATE_SET);
     final int[] FOCUSED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(FOCUSED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
     final int[] SELECTED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(SELECTED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
-    final int[] ENABLED_FOCUSED_SELECTED_STATE_SET =  stateSetUnion(ENABLED_FOCUSED_STATE_SET, SELECTED_STATE_SET);
+    final int[] ENABLED_FOCUSED_SELECTED_STATE_SET = stateSetUnion(ENABLED_FOCUSED_STATE_SET, SELECTED_STATE_SET);
     final int[] ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(ENABLED_FOCUSED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
     final int[] ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(ENABLED_SELECTED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
-    final int[] FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET =  stateSetUnion(FOCUSED_SELECTED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
+    final int[] FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(FOCUSED_SELECTED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
     final int[] ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(ENABLED_FOCUSED_SELECTED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
     final int[] PRESSED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(PRESSED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
     final int[] PRESSED_SELECTED_STATE_SET = stateSetUnion(PRESSED_STATE_SET, SELECTED_STATE_SET);
@@ -147,93 +142,97 @@ public class ExtractStyle {
     final int[] PRESSED_ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(PRESSED_ENABLED_FOCUSED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
     final int[] PRESSED_ENABLED_FOCUSED_SELECTED_STATE_SET = stateSetUnion(PRESSED_ENABLED_FOCUSED_STATE_SET, SELECTED_STATE_SET);
     final int[] PRESSED_ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET = stateSetUnion(PRESSED_ENABLED_FOCUSED_SELECTED_STATE_SET, WINDOW_FOCUSED_STATE_SET);
-
     final Resources.Theme m_theme;
     final String m_extractPath;
-    Context m_context;
     final int defaultBackgroundColor;
     final int defaultTextColor;
     final boolean m_minimal;
+    final int[] DrawableStates = { android.R.attr.state_active, android.R.attr.state_checked,
+            android.R.attr.state_enabled, android.R.attr.state_focused,
+            android.R.attr.state_pressed, android.R.attr.state_selected,
+            android.R.attr.state_window_focused, 16908288, android.R.attr.state_multiline,
+            android.R.attr.state_activated, android.R.attr.state_accelerated};
+    final String[] DrawableStatesLabels = {"active", "checked", "enabled", "focused", "pressed",
+            "selected", "window_focused", "background", "multiline", "activated", "accelerated"};
+    final String[] DisableDrawableStatesLabels = {"inactive", "unchecked", "disabled",
+            "not_focused", "no_pressed", "unselected", "window_not_focused", "background",
+            "multiline", "activated", "accelerated"};
+    final String[] sScaleTypeArray = {
+            "MATRIX",
+            "FIT_XY",
+            "FIT_START",
+            "FIT_CENTER",
+            "FIT_END",
+            "CENTER",
+            "CENTER_CROP",
+            "CENTER_INSIDE"
+    };
+    Context m_context;
+    private final HashMap<String, DrawableCache> m_drawableCache = new HashMap<>();
 
-    class SimpleJsonWriter
-    {
-        private OutputStreamWriter m_writer;
-        private boolean m_addComma = false;
-        private int m_indentLevel = 0;
-        public SimpleJsonWriter(String filePath) throws FileNotFoundException
-        {
-            m_writer = new OutputStreamWriter(new FileOutputStream(filePath));
-        }
-
-        public void close() throws IOException
-        {
-            m_writer.close();
-        }
-
-        private void writeIndent() throws IOException
-        {
-            m_writer.write(" ", 0, m_indentLevel);
-        }
-
-        SimpleJsonWriter beginObject() throws IOException
-        {
-            writeIndent();
-            m_writer.write("{\n");
-            ++m_indentLevel;
-            m_addComma = false;
-            return this;
-        }
-
-        SimpleJsonWriter endObject() throws IOException
-        {
-            m_writer.write("\n");
-            writeIndent();
-            m_writer.write("}\n");
-            --m_indentLevel;
-            m_addComma = false;
-            return this;
-        }
+    public ExtractStyle(Context context, String extractPath, boolean minimal) {
+        m_minimal = minimal;
+        m_extractPath = extractPath + "/";
+        boolean dirCreated = new File(m_extractPath).mkdirs();
+        if (!dirCreated)
+            Log.w(QtNative.QtTAG, "Cannot create Android style directory.");
+        m_context = context;
+        m_theme = context.getTheme();
+        TypedArray array = m_theme.obtainStyledAttributes(new int[]{
+                android.R.attr.colorBackground,
+                android.R.attr.textColorPrimary,
+                android.R.attr.textColor
+        });
+        defaultBackgroundColor = array.getColor(0, 0);
+        int textColor = array.getColor(1, 0xFFFFFF);
+        if (textColor == 0xFFFFFF)
+            textColor = array.getColor(2, 0xFFFFFF);
+        defaultTextColor = textColor;
+        array.recycle();
 
-        SimpleJsonWriter name(String name) throws IOException
-        {
-            if (m_addComma) {
-                m_writer.write(",\n");
+        try {
+            SimpleJsonWriter jsonWriter = new SimpleJsonWriter(m_extractPath + "style.json");
+            jsonWriter.beginObject();
+            try {
+                jsonWriter.name("defaultStyle").value(extractDefaultPalette());
+                extractWindow(jsonWriter);
+                jsonWriter.name("buttonStyle").value(extractTextAppearanceInformation(android.R.attr.buttonStyle, "QPushButton"));
+                jsonWriter.name("spinnerStyle").value(extractTextAppearanceInformation(android.R.attr.spinnerStyle, "QComboBox"));
+                extractProgressBar(jsonWriter, android.R.attr.progressBarStyleHorizontal, "progressBarStyleHorizontal", "QProgressBar");
+                extractProgressBar(jsonWriter, android.R.attr.progressBarStyleLarge, "progressBarStyleLarge", null);
+                extractProgressBar(jsonWriter, android.R.attr.progressBarStyleSmall, "progressBarStyleSmall", null);
+                extractProgressBar(jsonWriter, android.R.attr.progressBarStyle, "progressBarStyle", null);
+                extractAbsSeekBar(jsonWriter);
+                extractSwitch(jsonWriter);
+                extractCompoundButton(jsonWriter, android.R.attr.checkboxStyle, "checkboxStyle", "QCheckBox");
+                jsonWriter.name("editTextStyle").value(extractTextAppearanceInformation(android.R.attr.editTextStyle, "QLineEdit"));
+                extractCompoundButton(jsonWriter, android.R.attr.radioButtonStyle, "radioButtonStyle", "QRadioButton");
+                jsonWriter.name("textViewStyle").value(extractTextAppearanceInformation(android.R.attr.textViewStyle, "QWidget"));
+                jsonWriter.name("scrollViewStyle").value(extractTextAppearanceInformation(android.R.attr.scrollViewStyle, "QAbstractScrollArea"));
+                extractListView(jsonWriter);
+                jsonWriter.name("listSeparatorTextViewStyle").value(extractTextAppearanceInformation(android.R.attr.listSeparatorTextViewStyle, null));
+                extractItemsStyle(jsonWriter);
+                extractCompoundButton(jsonWriter, android.R.attr.buttonStyleToggle, "buttonStyleToggle", null);
+                extractCalendar(jsonWriter);
+                extractToolBar(jsonWriter);
+                jsonWriter.name("actionButtonStyle").value(extractTextAppearanceInformation(android.R.attr.actionButtonStyle, "QToolButton"));
+                jsonWriter.name("actionBarTabTextStyle").value(extractTextAppearanceInformation(android.R.attr.actionBarTabTextStyle, null));
+                jsonWriter.name("actionBarTabStyle").value(extractTextAppearanceInformation(android.R.attr.actionBarTabStyle, null));
+                jsonWriter.name("actionOverflowButtonStyle").value(extractImageViewInformation(android.R.attr.actionOverflowButtonStyle, null));
+                extractTabBar(jsonWriter);
+            } catch (Exception e) {
+                e.printStackTrace();
             }
-            writeIndent();
-            m_writer.write(JSONObject.quote(name) + ": ");
-            m_addComma = true;
-            return this;
-        }
-
-        SimpleJsonWriter value(JSONObject value) throws IOException
-        {
-            m_writer.write(value.toString());
-            return this;
+            jsonWriter.endObject();
+            jsonWriter.close();
+        } catch (Exception e) {
+            e.printStackTrace();
         }
     }
 
-    class FakeCanvas extends Canvas {
-        int[] chunkData = null;
-        class Size {
-            public int s,e;
-            Size(int start, int end)
-            {
-                s=start;
-                e=end;
-            }
-        }
-
-        public boolean isHardwareAccelerated() {
-            return true;
-        }
-
-        public void drawPatch(Bitmap bmp, byte[] chunks, RectF dst, Paint paint) {
-            chunkData = extractChunkInfo20(chunks);
-        }
-    }
+    native static int[] extractNativeChunkInfo20(long nativeChunk);
 
-    private int[] stateSetUnion(final int[] stateSet1, final int[] stateSet2)
-    {
+    private int[] stateSetUnion(final int[] stateSet1, final int[] stateSet2) {
         try {
             final int stateSet1Length = stateSet1.length;
             final int stateSet2Length = stateSet2.length;
@@ -251,12 +250,10 @@ public class ExtractStyle {
                     newSet[k++] = viewState;
                     j++;
                 }
-                if (k > 1) {
-                    assert(newSet[k - 1] > newSet[k - 2]);
-                }
+                assert k <= 1 || (newSet[k - 1] > newSet[k - 2]);
             }
             return newSet;
-        } catch(Exception e) {
+        } catch (Exception e) {
             e.printStackTrace();
         }
         return null;
@@ -291,21 +288,9 @@ public class ExtractStyle {
         return tryGetAccessibleField(clazz.getSuperclass(), fieldName);
     }
 
-    int getField(Class<?> clazz, String fieldName)
-    {
-        try {
-            return clazz.getDeclaredField(fieldName).getInt(null);
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-        return -1;
-    }
-
-    JSONObject getColorStateList(ColorStateList colorList)
-    {
+    JSONObject getColorStateList(ColorStateList colorList) {
         JSONObject json = new JSONObject();
-        try
-        {
+        try {
             json.put("EMPTY_STATE_SET", colorList.getColorForState(EMPTY_STATE_SET, 0));
             json.put("WINDOW_FOCUSED_STATE_SET", colorList.getColorForState(WINDOW_FOCUSED_STATE_SET, 0));
             json.put("SELECTED_STATE_SET", colorList.getColorForState(SELECTED_STATE_SET, 0));
@@ -345,150 +330,70 @@ public class ExtractStyle {
         return json;
     }
 
-    final int [] DrawableStates ={android.R.attr.state_active, android.R.attr.state_checked
-            , android.R.attr.state_enabled, android.R.attr.state_focused
-            , android.R.attr.state_pressed, android.R.attr.state_selected
-            , android.R.attr.state_window_focused, 16908288, 16843597, 16843518, 16843547};
-    final String[] DrawableStatesLabels = {"active", "checked", "enabled", "focused", "pressed", "selected", "window_focused", "background", "multiline", "activated", "accelerated"};
-    final String[] DisableDrawableStatesLabels = {"inactive", "unchecked", "disabled", "not_focused", "no_pressed", "unselected", "window_not_focused", "background", "multiline", "activated", "accelerated"};
-
-    String getFileName(String file, String[] states)
-    {
-        for (String state: states)
-            file+="__"+state;
-        return file;
-    }
-
-    String getStatesName(String[] states)
-    {
-        String statesName="";
-        for (String state: states)
-        {
-            if (statesName.length()>0)
-                statesName+="__";
-            statesName += state;
-        }
-        return statesName;
-    }
-
-    void addDrawableItemIfNotExists(JSONObject json, ArrayList<Integer> list, Drawable item, String[] states, String filename)
-    {
-        for (Integer it : list)
-        {
-            if (it.equals(item.hashCode()))
-                return;
-        }
-        list.add(item.hashCode());
-        try {
-            json.put(getStatesName(states), getDrawable(item, getFileName(filename, states), null));
-        } catch (JSONException e) {
-            e.printStackTrace();
-        }
-    }
-
-    void addSolution(String filename, JSONObject json, int c, Drawable drawable, ArrayList<Integer> drawableList, int u)
-    {
-        int pos=0;
-        int states[] = new int[c];
-        String [] statesText = new String[c];
-
-        for (int n= 0;u > 0;++n, u>>= 1)
-            if ((u & 1) > 0)
-            {
-                statesText[pos]=DrawableStatesLabels[n];
-                states[pos++]=DrawableStates[n];
-            }
-        drawable.setState(states);
-        addDrawableItemIfNotExists(json, drawableList, drawable.getCurrent(), statesText, filename);
-    }
-
-    int bitCount(int u)
-    {
-        int n;
-        for (n= 0;u > 0;++n, u&= (u - 1));
-        return n;
-    }
-
-    JSONObject getStatesList(int [] states) throws JSONException
-    {
+    JSONObject getStatesList(int[] states) throws JSONException {
         JSONObject json = new JSONObject();
-        for (int s : states)
-        {
-            boolean found=false;
-            for (int d = 0;d<DrawableStates.length;d++)
-            {
-                if (s==DrawableStates[d])
-                {
+        for (int s : states) {
+            boolean found = false;
+            for (int d = 0; d < DrawableStates.length; d++) {
+                if (s == DrawableStates[d]) {
                     json.put(DrawableStatesLabels[d], true);
-                    found=true;
+                    found = true;
                     break;
-                }
-                else if (s==-DrawableStates[d])
-                {
+                } else if (s == -DrawableStates[d]) {
                     json.put(DrawableStatesLabels[d], false);
 
-                    found=true;
+                    found = true;
                     break;
                 }
             }
-            if (!found)
-            {
-                json.put("unhandled_state_"+s,s>0);
+            if (!found) {
+                json.put("unhandled_state_" + s, s > 0);
             }
         }
         return json;
     }
 
-    String getStatesName(int [] states)
-    {
-        String statesName="";
-        for (int s : states)
-        {
-            boolean found=false;
-            for (int d = 0;d<DrawableStates.length;d++)
-            {
-                if (s==DrawableStates[d])
-                {
-                    if (statesName.length()>0)
-                        statesName+="__";
-                    statesName+=DrawableStatesLabels[d];
-                    found=true;
+    String getStatesName(int[] states) {
+        StringBuilder statesName = new StringBuilder();
+        for (int s : states) {
+            boolean found = false;
+            for (int d = 0; d < DrawableStates.length; d++) {
+                if (s == DrawableStates[d]) {
+                    if (statesName.length() > 0)
+                        statesName.append("__");
+                    statesName.append(DrawableStatesLabels[d]);
+                    found = true;
                     break;
-                }
-                else if (s==-DrawableStates[d])
-                {
-                    if (statesName.length()>0)
-                        statesName+="__";
-                    statesName+=DisableDrawableStatesLabels[d];
-                    found=true;
+                } else if (s == -DrawableStates[d]) {
+                    if (statesName.length() > 0)
+                        statesName.append("__");
+                    statesName.append(DisableDrawableStatesLabels[d]);
+                    found = true;
                     break;
                 }
             }
-            if (!found)
-            {
-                if (statesName.length()>0)
-                    statesName+=";";
-                statesName+=s;
+            if (!found) {
+                if (statesName.length() > 0)
+                    statesName.append(";");
+                statesName.append(s);
             }
         }
-        if (statesName.length()>0)
-            return statesName;
+        if (statesName.length() > 0)
+            return statesName.toString();
         return "empty";
     }
 
-    private JSONObject getLayerDrawable(Object drawable, String filename)
-    {
+    private JSONObject getLayerDrawable(Object drawable, String filename) {
         JSONObject json = new JSONObject();
         LayerDrawable layers = (LayerDrawable) drawable;
-        final int nr=layers.getNumberOfLayers();
+        final int nr = layers.getNumberOfLayers();
         try {
-            JSONArray array =new JSONArray();
-            for (int i = 0; i < nr; i++)
-            {
+            JSONArray array = new JSONArray();
+            for (int i = 0; i < nr; i++) {
                 int id = layers.getId(i);
                 if (id == -1)
                     id = i;
-                JSONObject layerJsonObject=getDrawable(layers.getDrawable(i), filename+"__"+id, null);
+                JSONObject layerJsonObject = getDrawable(layers.getDrawable(i), filename + "__" + id, null);
                 layerJsonObject.put("id", id);
                 array.put(layerJsonObject);
             }
@@ -503,21 +408,18 @@ public class ExtractStyle {
         return json;
     }
 
-    private JSONObject getStateListDrawable(Object drawable, String filename)
-    {
+    private JSONObject getStateListDrawable(Object drawable, String filename) {
         JSONObject json = new JSONObject();
         try {
             StateListDrawable stateList = (StateListDrawable) drawable;
-            final int numStates = (Integer) StateListDrawable.class.getMethod("getStateCount").invoke(stateList);
-            JSONArray array =new JSONArray();
-            for (int i = 0; i < numStates; i++)
-            {
+            JSONArray array = new JSONArray();
+            for (int i = 0; i < stateList.getStateCount(); i++) {
                 JSONObject stateJson = new JSONObject();
-                final Drawable d =  (Drawable) StateListDrawable.class.getMethod("getStateDrawable", Integer.TYPE).invoke(stateList, i);
-                final int [] states = (int[]) StateListDrawable.class.getMethod("getStateSet", Integer.TYPE).invoke(stateList, i);
+                final Drawable d = (Drawable) StateListDrawable.class.getMethod("getStateDrawable", Integer.TYPE).invoke(stateList, i);
+                final int[] states = (int[]) StateListDrawable.class.getMethod("getStateSet", Integer.TYPE).invoke(stateList, i);
                 if (states != null)
                     stateJson.put("states", getStatesList(states));
-                stateJson.put("drawable", getDrawable(d, filename+"__" + (states != null ? getStatesName(states) : ("state_pos_" + i)), null));
+                stateJson.put("drawable", getDrawable(d, filename + "__" + (states != null ? getStatesName(states) : ("state_pos_" + i)), null));
                 array.put(stateJson);
             }
             json.put("type", "stateslist");
@@ -535,32 +437,33 @@ public class ExtractStyle {
         JSONObject json = new JSONObject();
         try {
             json.put("type", "gradient");
-            Object obj=drawable.getConstantState();
-            Class<?> gradientStateClass=obj.getClass();
-            json.put("shape",gradientStateClass.getField("mShape").getInt(obj));
-            json.put("gradient",gradientStateClass.getField("mGradient").getInt(obj));
-            GradientDrawable.Orientation orientation=(Orientation) gradientStateClass.getField("mOrientation").get(obj);
-            json.put("orientation",orientation.name());
-            int [] intArray=(int[]) gradientStateClass.getField("mGradientColors").get(obj);
+            Object obj = drawable.getConstantState();
+            Class<?> gradientStateClass = obj.getClass();
+            json.put("shape", gradientStateClass.getField("mShape").getInt(obj));
+            json.put("gradient", gradientStateClass.getField("mGradient").getInt(obj));
+            GradientDrawable.Orientation orientation = (Orientation) gradientStateClass.getField("mOrientation").get(obj);
+            if (orientation != null)
+                json.put("orientation", orientation.name());
+            int[] intArray = (int[]) gradientStateClass.getField("mGradientColors").get(obj);
             if (intArray != null)
-                json.put("colors",getJsonArray(intArray, 0, intArray.length));
-            json.put("positions",getJsonArray((float[]) gradientStateClass.getField("mPositions").get(obj)));
-            json.put("strokeWidth",gradientStateClass.getField("mStrokeWidth").getInt(obj));
-            json.put("strokeDashWidth",gradientStateClass.getField("mStrokeDashWidth").getFloat(obj));
-            json.put("strokeDashGap",gradientStateClass.getField("mStrokeDashGap").getFloat(obj));
-            json.put("radius",gradientStateClass.getField("mRadius").getFloat(obj));
-            float [] floatArray=(float[]) gradientStateClass.getField("mRadiusArray").get(obj);
-            if (floatArray!=null)
-                json.put("radiusArray",getJsonArray(floatArray));
-            Rect rc= (Rect) gradientStateClass.getField("mPadding").get(obj);
-            if (rc!=null)
-                json.put("padding",getJsonRect(rc));
-            json.put("width",gradientStateClass.getField("mWidth").getInt(obj));
-            json.put("height",gradientStateClass.getField("mHeight").getInt(obj));
-            json.put("innerRadiusRatio",gradientStateClass.getField("mInnerRadiusRatio").getFloat(obj));
-            json.put("thicknessRatio",gradientStateClass.getField("mThicknessRatio").getFloat(obj));
-            json.put("innerRadius",gradientStateClass.getField("mInnerRadius").getInt(obj));
-            json.put("thickness",gradientStateClass.getField("mThickness").getInt(obj));
+                json.put("colors", getJsonArray(intArray, 0, intArray.length));
+            json.put("positions", getJsonArray((float[]) gradientStateClass.getField("mPositions").get(obj)));
+            json.put("strokeWidth", gradientStateClass.getField("mStrokeWidth").getInt(obj));
+            json.put("strokeDashWidth", gradientStateClass.getField("mStrokeDashWidth").getFloat(obj));
+            json.put("strokeDashGap", gradientStateClass.getField("mStrokeDashGap").getFloat(obj));
+            json.put("radius", gradientStateClass.getField("mRadius").getFloat(obj));
+            float[] floatArray = (float[]) gradientStateClass.getField("mRadiusArray").get(obj);
+            if (floatArray != null)
+                json.put("radiusArray", getJsonArray(floatArray));
+            Rect rc = (Rect) gradientStateClass.getField("mPadding").get(obj);
+            if (rc != null)
+                json.put("padding", getJsonRect(rc));
+            json.put("width", gradientStateClass.getField("mWidth").getInt(obj));
+            json.put("height", gradientStateClass.getField("mHeight").getInt(obj));
+            json.put("innerRadiusRatio", gradientStateClass.getField("mInnerRadiusRatio").getFloat(obj));
+            json.put("thicknessRatio", gradientStateClass.getField("mThicknessRatio").getFloat(obj));
+            json.put("innerRadius", gradientStateClass.getField("mInnerRadius").getInt(obj));
+            json.put("thickness", gradientStateClass.getField("mThickness").getInt(obj));
         } catch (Exception e) {
             e.printStackTrace();
         }
@@ -573,10 +476,7 @@ public class ExtractStyle {
             json.put("type", "rotate");
             Object obj = drawable.getConstantState();
             Class<?> rotateStateClass = obj.getClass();
-            if (Build.VERSION.SDK_INT < 23)
-                json.put("drawable", getDrawable(getAccessibleField(rotateStateClass, "mDrawable").get(obj), filename, null));
-            else
-                json.put("drawable", getDrawable(drawable.getClass().getMethod("getDrawable").invoke(drawable), filename, null));
+            json.put("drawable", getDrawable(drawable.getClass().getMethod("getDrawable").invoke(drawable), filename, null));
             json.put("pivotX", getAccessibleField(rotateStateClass, "mPivotX").getFloat(obj));
             json.put("pivotXRel", getAccessibleField(rotateStateClass, "mPivotXRel").getBoolean(obj));
             json.put("pivotY", getAccessibleField(rotateStateClass, "mPivotY").getFloat(obj));
@@ -596,11 +496,10 @@ public class ExtractStyle {
             json.put("oneshot", drawable.isOneShot());
             final int count = drawable.getNumberOfFrames();
             JSONArray frames = new JSONArray();
-            for (int i = 0; i < count; ++i)
-            {
+            for (int i = 0; i < count; ++i) {
                 JSONObject frame = new JSONObject();
                 frame.put("duration", drawable.getDuration(i));
-                frame.put("drawable", getDrawable(drawable.getFrame(i), filename+"__"+i, null));
+                frame.put("drawable", getDrawable(drawable.getFrame(i), filename + "__" + i, null));
                 frames.put(frame);
             }
             json.put("frames", frames);
@@ -610,8 +509,7 @@ public class ExtractStyle {
         return json;
     }
 
-    private JSONObject getJsonRect(Rect rect) throws JSONException
-    {
+    private JSONObject getJsonRect(Rect rect) throws JSONException {
         JSONObject jsonRect = new JSONObject();
         jsonRect.put("left", rect.left);
         jsonRect.put("top", rect.top);
@@ -621,26 +519,23 @@ public class ExtractStyle {
 
     }
 
-    private JSONArray getJsonArray(int[] array, int pos, int len)
-    {
+    private JSONArray getJsonArray(int[] array, int pos, int len) {
         JSONArray a = new JSONArray();
-        final int l = pos+len;
-        for (int i=pos; i<l;i++)
+        final int l = pos + len;
+        for (int i = pos; i < l; i++)
             a.put(array[i]);
         return a;
     }
 
-    private JSONArray getJsonArray(float[] array) throws JSONException
-    {
+    private JSONArray getJsonArray(float[] array) throws JSONException {
         JSONArray a = new JSONArray();
         if (array != null)
-            for (float val: array)
+            for (float val : array)
                 a.put(val);
         return a;
     }
 
-    private JSONObject getJsonChunkInfo(int[] chunkData) throws JSONException
-    {
+    private JSONObject getJsonChunkInfo(int[] chunkData) throws JSONException {
         JSONObject jsonRect = new JSONObject();
         if (chunkData == null)
             return jsonRect;
@@ -651,41 +546,31 @@ public class ExtractStyle {
         return jsonRect;
     }
 
-    private JSONObject findPatchesMarings(Drawable d) throws JSONException, NoSuchFieldException, IllegalAccessException
-    {
+    private JSONObject findPatchesMarings(Drawable d) throws JSONException, IllegalAccessException {
         NinePatch np;
         Field f = tryGetAccessibleField(NinePatchDrawable.class, "mNinePatch");
         if (f != null) {
             np = (NinePatch) f.get(d);
         } else {
             Object state = getAccessibleField(NinePatchDrawable.class, "mNinePatchState").get(d);
-            np = (NinePatch) getAccessibleField(state.getClass(), "mNinePatch").get(state);
+            np = (NinePatch) getAccessibleField(Objects.requireNonNull(state).getClass(), "mNinePatch").get(state);
         }
-        return getJsonChunkInfo(extractNativeChunkInfo20(getAccessibleField(np.getClass(), "mNativeChunk").getLong(np)));
+        return getJsonChunkInfo(extractNativeChunkInfo20(getAccessibleField(Objects.requireNonNull(np).getClass(), "mNativeChunk").getLong(np)));
     }
 
-    class DrawableCache
-    {
-        public DrawableCache(JSONObject json, Object drawable)
-        {
-            object = json;
-            this.drawable = drawable;
-        }
-        JSONObject object;
-        Object drawable;
-    }
-    private HashMap<String, DrawableCache> m_drawableCache = new HashMap<String, DrawableCache>();
-
-    private JSONObject getRippleDrawable(Object drawable, String filename, Rect padding)
-    {
+    private JSONObject getRippleDrawable(Object drawable, String filename, Rect padding) {
         JSONObject json = getLayerDrawable(drawable, filename);
-        JSONObject ripple =  new JSONObject();
+        JSONObject ripple = new JSONObject();
         try {
             Class<?> rippleDrawableClass = Class.forName("android.graphics.drawable.RippleDrawable");
             final Object mState = getAccessibleField(rippleDrawableClass, "mState").get(drawable);
-            ripple.put("mask", getDrawable((Drawable)getAccessibleField(rippleDrawableClass, "mMask").get(drawable), filename, padding));
-            ripple.put("maxRadius", getAccessibleField(mState.getClass(), "mMaxRadius").getInt(mState));
-            ripple.put("color", getColorStateList((ColorStateList)getAccessibleField(mState.getClass(), "mColor").get(mState)));
+            ripple.put("mask", getDrawable((Drawable) getAccessibleField(rippleDrawableClass, "mMask").get(drawable), filename, padding));
+            if (mState != null) {
+                ripple.put("maxRadius", getAccessibleField(mState.getClass(), "mMaxRadius").getInt(mState));
+                ColorStateList color = (ColorStateList) getAccessibleField(mState.getClass(), "mColor").get(mState);
+                if (color != null)
+                    ripple.put("color", getColorStateList(color));
+            }
             json.put("ripple", ripple);
         } catch (Exception e) {
             e.printStackTrace();
@@ -693,32 +578,31 @@ public class ExtractStyle {
         return json;
     }
 
-    private HashMap<Long, Long> getStateTransitions(Object sa) throws Exception
-    {
-        HashMap<Long, Long> transitions = new HashMap<Long, Long>();
+    private HashMap<Long, Long> getStateTransitions(Object sa) throws Exception {
+        HashMap<Long, Long> transitions = new HashMap<>();
         final int sz = getAccessibleField(sa.getClass(), "mSize").getInt(sa);
         long[] keys = (long[]) getAccessibleField(sa.getClass(), "mKeys").get(sa);
         long[] values = (long[]) getAccessibleField(sa.getClass(), "mValues").get(sa);
         for (int i = 0; i < sz; i++) {
-            transitions.put(keys[i], values[i]);
+            if (keys != null && values != null)
+                transitions.put(keys[i], values[i]);
         }
         return transitions;
     }
 
-    private HashMap<Integer, Integer> getStateIds(Object sa) throws Exception
-    {
-        HashMap<Integer, Integer> states = new HashMap<Integer, Integer>();
+    private HashMap<Integer, Integer> getStateIds(Object sa) throws Exception {
+        HashMap<Integer, Integer> states = new HashMap<>();
         final int sz = getAccessibleField(sa.getClass(), "mSize").getInt(sa);
         int[] keys = (int[]) getAccessibleField(sa.getClass(), "mKeys").get(sa);
         int[] values = (int[]) getAccessibleField(sa.getClass(), "mValues").get(sa);
         for (int i = 0; i < sz; i++) {
-            states.put(keys[i], values[i]);
+            if (keys != null && values != null)
+                states.put(keys[i], values[i]);
         }
         return states;
     }
 
-    private int findStateIndex(int id, HashMap<Integer, Integer> stateIds)
-    {
+    private int findStateIndex(int id, HashMap<Integer, Integer> stateIds) {
         for (Map.Entry<Integer, Integer> s : stateIds.entrySet()) {
             if (id == s.getValue())
                 return s.getKey();
@@ -726,28 +610,30 @@ public class ExtractStyle {
         return -1;
     }
 
-    private JSONObject getAnimatedStateListDrawable(Object drawable, String filename)
-    {
+    private JSONObject getAnimatedStateListDrawable(Object drawable, String filename) {
         JSONObject json = getStateListDrawable(drawable, filename);
         try {
             Class<?> animatedStateListDrawableClass = Class.forName("android.graphics.drawable.AnimatedStateListDrawable");
             Object state = getAccessibleField(animatedStateListDrawableClass, "mState").get(drawable);
 
-            HashMap<Integer, Integer> stateIds = getStateIds(getAccessibleField(state.getClass(), "mStateIds").get(state));
-            HashMap<Long, Long> transitions = getStateTransitions(getAccessibleField(state.getClass(), "mTransitions").get(state));
+            if (state != null) {
+                Class<?> stateClass = state.getClass();
+                HashMap<Integer, Integer> stateIds = getStateIds(Objects.requireNonNull(getAccessibleField(stateClass, "mStateIds").get(state)));
+                HashMap<Long, Long> transitions = getStateTransitions(Objects.requireNonNull(getAccessibleField(stateClass, "mTransitions").get(state)));
 
-            for (Map.Entry<Long, Long> t : transitions.entrySet()) {
-                final int toState = findStateIndex(t.getKey().intValue(), stateIds);
-                final int fromState = findStateIndex((int) (t.getKey() >> 32), stateIds);
+                for (Map.Entry<Long, Long> t : transitions.entrySet()) {
+                    final int toState = findStateIndex(t.getKey().intValue(), stateIds);
+                    final int fromState = findStateIndex((int) (t.getKey() >> 32), stateIds);
 
-                JSONObject transition = new JSONObject();
-                transition.put("from", fromState);
-                transition.put("to", toState);
-                transition.put("reverse", (t.getValue() >> 32) != 0);
+                    JSONObject transition = new JSONObject();
+                    transition.put("from", fromState);
+                    transition.put("to", toState);
+                    transition.put("reverse", (t.getValue() >> 32) != 0);
 
-                JSONArray stateslist = json.getJSONArray("stateslist");
-                JSONObject stateobj = stateslist.getJSONObject(t.getValue().intValue());
-                stateobj.put("transition", transition);
+                    JSONArray stateslist = json.getJSONArray("stateslist");
+                    JSONObject stateobj = stateslist.getJSONObject(t.getValue().intValue());
+                    stateobj.put("transition", transition);
+                }
             }
         } catch (Exception e) {
             e.printStackTrace();
@@ -755,21 +641,22 @@ public class ExtractStyle {
         return json;
     }
 
-    private JSONObject getVPath(Object path) throws Exception
-    {
+    private JSONObject getVPath(Object path) throws Exception {
         JSONObject json = new JSONObject();
         final Class<?> pathClass = path.getClass();
         json.put("type", "path");
         json.put("name", tryGetAccessibleField(pathClass, "mPathName").get(path));
         Object[] mNodes = (Object[]) tryGetAccessibleField(pathClass, "mNodes").get(path);
         JSONArray nodes = new JSONArray();
-        for (Object n: mNodes) {
-            JSONObject node = new JSONObject();
-            node.put("type", String.valueOf(getAccessibleField(n.getClass(), "mType").getChar(n)));
-            node.put("params", getJsonArray((float[])getAccessibleField(n.getClass(), "mParams").get(n)));
-            nodes.put(node);
+        if (mNodes != null) {
+            for (Object n : mNodes) {
+                JSONObject node = new JSONObject();
+                node.put("type", String.valueOf(getAccessibleField(n.getClass(), "mType").getChar(n)));
+                node.put("params", getJsonArray((float[]) getAccessibleField(n.getClass(), "mParams").get(n)));
+                nodes.put(node);
+            }
+            json.put("nodes", nodes);
         }
-        json.put("nodes", nodes);
         json.put("isClip", (Boolean) pathClass.getMethod("isClipPath").invoke(path));
 
         if (tryGetAccessibleField(pathClass, "mStrokeColor") == null)
@@ -791,8 +678,7 @@ public class ExtractStyle {
     }
 
     @SuppressWarnings("unchecked")
-    private JSONObject getVGroup(Object group) throws Exception
-    {
+    private JSONObject getVGroup(Object group) throws Exception {
         JSONObject json = new JSONObject();
         json.put("type", "group");
         final Class<?> groupClass = group.getClass();
@@ -807,65 +693,63 @@ public class ExtractStyle {
 
         ArrayList<Object> mChildren = (ArrayList<Object>) getAccessibleField(groupClass, "mChildren").get(group);
         JSONArray children = new JSONArray();
-        for (Object c: mChildren) {
-            if (groupClass.isInstance(c))
-                children.put(getVGroup(c));
-            else
-                children.put(getVPath(c));
+        if (mChildren != null) {
+            for (Object c : mChildren) {
+                if (groupClass.isInstance(c))
+                    children.put(getVGroup(c));
+                else
+                    children.put(getVPath(c));
+            }
+            json.put("children", children);
         }
-        json.put("children", children);
         return json;
     }
 
-    private JSONObject getVectorDrawable(Object drawable, String filename, Rect padding)
-    {
+    private JSONObject getVectorDrawable(Object drawable) {
         JSONObject json = new JSONObject();
         try {
             json.put("type", "vector");
             Class<?> vectorDrawableClass = Class.forName("android.graphics.drawable.VectorDrawable");
             final Object state = getAccessibleField(vectorDrawableClass, "mVectorState").get(drawable);
-            final Class<?> stateClass = state.getClass();
+            final Class<?> stateClass = Objects.requireNonNull(state).getClass();
             final ColorStateList mTint = (ColorStateList) getAccessibleField(stateClass, "mTint").get(state);
             if (mTint != null) {
                 json.put("tintList", getColorStateList(mTint));
                 json.put("tintMode", (PorterDuff.Mode) getAccessibleField(stateClass, "mTintMode").get(state));
             }
             final Object mVPathRenderer = getAccessibleField(stateClass, "mVPathRenderer").get(state);
-            final Class<?> VPathRendererClass = mVPathRenderer.getClass();
+            final Class<?> VPathRendererClass = Objects.requireNonNull(mVPathRenderer).getClass();
             json.put("baseWidth", getAccessibleField(VPathRendererClass, "mBaseWidth").getFloat(mVPathRenderer));
             json.put("baseHeight", getAccessibleField(VPathRendererClass, "mBaseHeight").getFloat(mVPathRenderer));
             json.put("viewportWidth", getAccessibleField(VPathRendererClass, "mViewportWidth").getFloat(mVPathRenderer));
             json.put("viewportHeight", getAccessibleField(VPathRendererClass, "mViewportHeight").getFloat(mVPathRenderer));
             json.put("rootAlpha", getAccessibleField(VPathRendererClass, "mRootAlpha").getInt(mVPathRenderer));
             json.put("rootName", getAccessibleField(VPathRendererClass, "mRootName").get(mVPathRenderer));
-            json.put("rootGroup", getVGroup(getAccessibleField(mVPathRenderer.getClass(), "mRootGroup").get(mVPathRenderer)));
-        } catch(Exception e) {
+            json.put("rootGroup", getVGroup(Objects.requireNonNull(getAccessibleField(VPathRendererClass, "mRootGroup").get(mVPathRenderer))));
+        } catch (Exception e) {
             e.printStackTrace();
         }
         return json;
     }
 
-    public JSONObject getDrawable(Object drawable, String filename, Rect padding)
-    {
+    public JSONObject getDrawable(Object drawable, String filename, Rect padding) {
         if (drawable == null || m_minimal)
             return null;
 
         DrawableCache dc = m_drawableCache.get(filename);
-        if (dc != null)
-        {
+        if (dc != null) {
             if (dc.drawable.equals(drawable))
                 return dc.object;
             else
-                Log.e(QtNative.QtTAG, "Different drawable objects points to the same file name \"" + filename +"\"");
+                Log.e(QtNative.QtTAG, "Different drawable objects points to the same file name \"" + filename + "\"");
         }
         JSONObject json = new JSONObject();
         Bitmap bmp = null;
         if (drawable instanceof Bitmap)
             bmp = (Bitmap) drawable;
-        else
-        {
+        else {
             if (drawable instanceof BitmapDrawable) {
-                BitmapDrawable bitmapDrawable = (BitmapDrawable)drawable;
+                BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
                 bmp = bitmapDrawable.getBitmap();
                 try {
                     json.put("gravity", bitmapDrawable.getGravity());
@@ -880,48 +764,39 @@ public class ExtractStyle {
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
-            }
-            else
-            {
+            } else {
 
-                if (drawable instanceof RippleDrawable )
+                if (drawable instanceof RippleDrawable)
                     return getRippleDrawable(drawable, filename, padding);
 
                 if (drawable instanceof AnimatedStateListDrawable)
                     return getAnimatedStateListDrawable(drawable, filename);
 
                 if (drawable instanceof VectorDrawable)
-                    return getVectorDrawable(drawable, filename, padding);
+                    return getVectorDrawable(drawable);
 
-                if (drawable instanceof ScaleDrawable)
-                {
-                    return getDrawable(((ScaleDrawable)drawable).getDrawable(), filename, null);
+                if (drawable instanceof ScaleDrawable) {
+                    return getDrawable(((ScaleDrawable) drawable).getDrawable(), filename, null);
                 }
-                if (drawable instanceof LayerDrawable)
-                {
+                if (drawable instanceof LayerDrawable) {
                     return getLayerDrawable(drawable, filename);
                 }
-                if (drawable instanceof StateListDrawable)
-                {
+                if (drawable instanceof StateListDrawable) {
                     return getStateListDrawable(drawable, filename);
                 }
-                if (drawable instanceof GradientDrawable)
-                {
+                if (drawable instanceof GradientDrawable) {
                     return getGradientDrawable((GradientDrawable) drawable);
                 }
-                if (drawable instanceof RotateDrawable)
-                {
+                if (drawable instanceof RotateDrawable) {
                     return getRotateDrawable((RotateDrawable) drawable, filename);
                 }
-                if (drawable instanceof AnimationDrawable)
-                {
+                if (drawable instanceof AnimationDrawable) {
                     return getAnimationDrawable((AnimationDrawable) drawable, filename);
                 }
-                if (drawable instanceof ClipDrawable)
-                {
+                if (drawable instanceof ClipDrawable) {
                     try {
                         json.put("type", "clipDrawable");
-                        Drawable.ConstantState dcs = ((ClipDrawable)drawable).getConstantState();
+                        Drawable.ConstantState dcs = ((ClipDrawable) drawable).getConstantState();
                         json.put("drawable", getDrawable(getAccessibleField(dcs.getClass(), "mDrawable").get(dcs), filename, null));
                         if (null != padding)
                             json.put("padding", getJsonRect(padding));
@@ -935,8 +810,7 @@ public class ExtractStyle {
                     }
                     return json;
                 }
-                if (drawable instanceof ColorDrawable)
-                {
+                if (drawable instanceof ColorDrawable) {
                     bmp = Bitmap.createBitmap(1, 1, Config.ARGB_8888);
                     Drawable d = (Drawable) drawable;
                     d.setBounds(0, 0, 1, 1);
@@ -956,34 +830,29 @@ public class ExtractStyle {
                     }
                     return json;
                 }
-                if (drawable instanceof InsetDrawable)
-                {
+                if (drawable instanceof InsetDrawable) {
                     try {
-                        InsetDrawable d = (InsetDrawable)drawable;
+                        InsetDrawable d = (InsetDrawable) drawable;
                         Object mInsetStateObject = getAccessibleField(InsetDrawable.class, "mState").get(d);
                         Rect _padding = new Rect();
                         boolean hasPadding = d.getPadding(_padding);
-                        return getDrawable(getAccessibleField(mInsetStateObject.getClass(), "mDrawable").get(mInsetStateObject), filename, hasPadding ? _padding : null);
+                        return getDrawable(getAccessibleField(Objects.requireNonNull(mInsetStateObject).getClass(), "mDrawable").get(mInsetStateObject), filename, hasPadding ? _padding : null);
                     } catch (Exception e) {
                         e.printStackTrace();
                     }
-                }
-                else
-                {
+                } else {
                     Drawable d = (Drawable) drawable;
-                    int w=d.getIntrinsicWidth();
-                    int h=d.getIntrinsicHeight();
+                    int w = d.getIntrinsicWidth();
+                    int h = d.getIntrinsicHeight();
                     d.setLevel(10000);
-                    if (w<1 || h< 1)
-                    {
-                        w=100;
-                        h=100;
+                    if (w < 1 || h < 1) {
+                        w = 100;
+                        h = 100;
                     }
                     bmp = Bitmap.createBitmap(w, h, Config.ARGB_8888);
                     d.setBounds(0, 0, w, h);
                     d.draw(new Canvas(bmp));
-                    if (drawable instanceof NinePatchDrawable)
-                    {
+                    if (drawable instanceof NinePatchDrawable) {
                         NinePatchDrawable npd = (NinePatchDrawable) drawable;
                         try {
                             json.put("type", "9patch");
@@ -1007,20 +876,21 @@ public class ExtractStyle {
         }
         FileOutputStream out;
         try {
-            filename = m_extractPath+filename+".png";
+            filename = m_extractPath + filename + ".png";
             out = new FileOutputStream(filename);
-            bmp.compress(Bitmap.CompressFormat.PNG, 100, out);
+            if (bmp != null)
+                bmp.compress(Bitmap.CompressFormat.PNG, 100, out);
             out.close();
-        } catch (FileNotFoundException e) {
-            e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
         try {
             json.put("type", "image");
             json.put("path", filename);
-            json.put("width", bmp.getWidth());
-            json.put("height", bmp.getHeight());
+            if (bmp != null) {
+                json.put("width", bmp.getWidth());
+                json.put("height", bmp.getHeight());
+            }
             m_drawableCache.put(filename, new DrawableCache(json, drawable));
         } catch (JSONException e) {
             e.printStackTrace();
@@ -1036,8 +906,7 @@ public class ExtractStyle {
         return ctx.obtainStyledAttributes(typedValue.data, attributes);
     }
 
-    private ArrayList<Integer> getArrayListFromIntArray(int[] attributes)
-    {
+    private ArrayList<Integer> getArrayListFromIntArray(int[] attributes) {
         ArrayList<Integer> sortedAttrs = new ArrayList<>();
         for (int attr : attributes)
             sortedAttrs.add(attr);
@@ -1249,7 +1118,7 @@ public class ExtractStyle {
             ctx.getTheme().resolveAttribute(styleName, typedValue, true);
 
             // Get textAppearance values
-            int[] textAppearanceAttr = new int[]{ textAppearance };
+            int[] textAppearanceAttr = new int[]{textAppearance};
             TypedArray textAppearanceArray = ctx.obtainStyledAttributes(typedValue.data, textAppearanceAttr);
             int textAppearanceId = textAppearanceArray.getResourceId(0, -1);
             textAppearanceArray.recycle();
@@ -1468,19 +1337,7 @@ public class ExtractStyle {
         return json;
     }
 
-    final String[] sScaleTypeArray = {
-            "MATRIX",
-            "FIT_XY",
-            "FIT_START",
-            "FIT_CENTER",
-            "FIT_END",
-            "CENTER",
-            "CENTER_CROP",
-            "CENTER_INSIDE"
-    };
-
-    public JSONObject extractImageViewInformation(int styleName, String qtClassName)
-    {
+    public JSONObject extractImageViewInformation(int styleName, String qtClassName) {
         JSONObject json = new JSONObject();
         try {
             extractViewInformation(styleName, json, qtClassName);
@@ -1524,8 +1381,7 @@ public class ExtractStyle {
         return json;
     }
 
-    void extractCompoundButton(SimpleJsonWriter jsonWriter, int styleName, String className, String qtClass)
-    {
+    void extractCompoundButton(SimpleJsonWriter jsonWriter, int styleName, String className, String qtClass) {
         JSONObject json = extractTextAppearanceInformation(styleName, qtClass);
 
         TypedValue typedValue = new TypedValue();
@@ -1545,8 +1401,7 @@ public class ExtractStyle {
         }
     }
 
-    void extractProgressBarInfo(JSONObject json, int styleName)
-    {
+    void extractProgressBarInfo(JSONObject json, int styleName) {
         try {
             final int[] attributes = new int[]{
                     android.R.attr.minWidth,
@@ -1588,8 +1443,7 @@ public class ExtractStyle {
         }
     }
 
-    void extractProgressBar(SimpleJsonWriter writer, int styleName, String className, String qtClass)
-    {
+    void extractProgressBar(SimpleJsonWriter writer, int styleName, String className, String qtClass) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.progressBarStyle, qtClass);
         try {
             extractProgressBarInfo(json, styleName);
@@ -1599,9 +1453,7 @@ public class ExtractStyle {
         }
     }
 
-
-    void extractAbsSeekBar(SimpleJsonWriter jsonWriter)
-    {
+    void extractAbsSeekBar(SimpleJsonWriter jsonWriter) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.seekBarStyle, "QSlider");
         extractProgressBarInfo(json, android.R.attr.seekBarStyle);
         try {
@@ -1624,8 +1476,7 @@ public class ExtractStyle {
         }
     }
 
-    void extractSwitch(SimpleJsonWriter jsonWriter)
-    {
+    void extractSwitch(SimpleJsonWriter jsonWriter) {
         JSONObject json = new JSONObject();
         try {
             int[] attributes = new int[]{
@@ -1671,8 +1522,7 @@ public class ExtractStyle {
         }
     }
 
-    JSONObject extractCheckedTextView(String itemName)
-    {
+    JSONObject extractCheckedTextView(String itemName) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.checkedTextViewStyle, itemName);
         try {
             int[] attributes = new int[]{
@@ -1716,8 +1566,7 @@ public class ExtractStyle {
         return null;
     }
 
-    private void extractItemsStyle(SimpleJsonWriter jsonWriter)
-    {
+    private void extractItemsStyle(SimpleJsonWriter jsonWriter) {
         try {
             JSONObject itemStyle = extractItemStyle(android.R.layout.simple_list_item_1, "simple_list_item");
             if (itemStyle != null)
@@ -1748,8 +1597,7 @@ public class ExtractStyle {
         }
     }
 
-    void extractListView(SimpleJsonWriter writer)
-    {
+    void extractListView(SimpleJsonWriter writer) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.listViewStyle, "QListView");
         try {
             int[] attributes = new int[]{
@@ -1773,8 +1621,7 @@ public class ExtractStyle {
         }
     }
 
-    void extractCalendar(SimpleJsonWriter writer)
-    {
+    void extractCalendar(SimpleJsonWriter writer) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.calendarViewStyle, "QCalendarWidget");
         try {
             int[] attributes = new int[]{
@@ -1819,11 +1666,10 @@ public class ExtractStyle {
         }
     }
 
-    void extractToolBar(SimpleJsonWriter writer)
-    {
+    void extractToolBar(SimpleJsonWriter writer) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.toolbarStyle, "QToolBar");
         try {
-            int[] attributes = new int[] {
+            int[] attributes = new int[]{
                     android.R.attr.background,
                     android.R.attr.backgroundStacked,
                     android.R.attr.backgroundSplit,
@@ -1859,8 +1705,7 @@ public class ExtractStyle {
         }
     }
 
-    void extractTabBar(SimpleJsonWriter writer)
-    {
+    void extractTabBar(SimpleJsonWriter writer) {
         JSONObject json = extractTextAppearanceInformation(android.R.attr.actionBarTabBarStyle, "QTabBar");
         try {
             int[] attributes = new int[]{
@@ -1885,8 +1730,7 @@ public class ExtractStyle {
         }
     }
 
-    private void extractWindow(SimpleJsonWriter writer)
-    {
+    private void extractWindow(SimpleJsonWriter writer) {
         JSONObject json = new JSONObject();
         try {
             int[] attributes = new int[]{
@@ -1911,8 +1755,7 @@ public class ExtractStyle {
         }
     }
 
-    private JSONObject extractDefaultPalette()
-    {
+    private JSONObject extractDefaultPalette() {
         JSONObject json = extractTextAppearance(android.R.attr.textAppearance);
         try {
             json.put("defaultBackgroundColor", defaultBackgroundColor);
@@ -1923,64 +1766,59 @@ public class ExtractStyle {
         return json;
     }
 
-    public ExtractStyle(Context context, String extractPath, boolean minimal)
-    {
-        m_minimal = minimal;
-        m_extractPath = extractPath + "/";
-        new File(m_extractPath).mkdirs();
-        m_context = context;
-        m_theme = context.getTheme();
-        TypedArray array = m_theme.obtainStyledAttributes(new int[]{
-                android.R.attr.colorBackground,
-                android.R.attr.textColorPrimary,
-                android.R.attr.textColor
-        });
-        defaultBackgroundColor = array.getColor(0, 0);
-        int textColor = array.getColor(1, 0xFFFFFF);
-        if (textColor == 0xFFFFFF)
-            textColor = array.getColor(2, 0xFFFFFF);
-        defaultTextColor = textColor;
-        array.recycle();
+    static class SimpleJsonWriter {
+        private final OutputStreamWriter m_writer;
+        private boolean m_addComma = false;
+        private int m_indentLevel = 0;
 
-        try
-        {
-            SimpleJsonWriter jsonWriter = new SimpleJsonWriter(m_extractPath+"style.json");
-            jsonWriter.beginObject();
-            try {
-                jsonWriter.name("defaultStyle").value(extractDefaultPalette());
-                extractWindow(jsonWriter);
-                jsonWriter.name("buttonStyle").value(extractTextAppearanceInformation(android.R.attr.buttonStyle, "QPushButton"));
-                jsonWriter.name("spinnerStyle").value(extractTextAppearanceInformation(android.R.attr.spinnerStyle, "QComboBox"));
-                extractProgressBar(jsonWriter, android.R.attr.progressBarStyleHorizontal, "progressBarStyleHorizontal", "QProgressBar");
-                extractProgressBar(jsonWriter, android.R.attr.progressBarStyleLarge, "progressBarStyleLarge", null);
-                extractProgressBar(jsonWriter, android.R.attr.progressBarStyleSmall, "progressBarStyleSmall", null);
-                extractProgressBar(jsonWriter, android.R.attr.progressBarStyle, "progressBarStyle", null);
-                extractAbsSeekBar(jsonWriter);
-                extractSwitch(jsonWriter);
-                extractCompoundButton(jsonWriter, android.R.attr.checkboxStyle, "checkboxStyle", "QCheckBox");
-                jsonWriter.name("editTextStyle").value(extractTextAppearanceInformation(android.R.attr.editTextStyle, "QLineEdit"));
-                extractCompoundButton(jsonWriter, android.R.attr.radioButtonStyle, "radioButtonStyle", "QRadioButton");
-                jsonWriter.name("textViewStyle").value(extractTextAppearanceInformation(android.R.attr.textViewStyle, "QWidget"));
-                jsonWriter.name("scrollViewStyle").value(extractTextAppearanceInformation(android.R.attr.scrollViewStyle, "QAbstractScrollArea"));
-                extractListView(jsonWriter);
-                jsonWriter.name("listSeparatorTextViewStyle").value(extractTextAppearanceInformation(android.R.attr.listSeparatorTextViewStyle, null));
-                extractItemsStyle(jsonWriter);
-                extractCompoundButton(jsonWriter, android.R.attr.buttonStyleToggle, "buttonStyleToggle", null);
-                extractCalendar(jsonWriter);
-                extractToolBar(jsonWriter);
-                jsonWriter.name("actionButtonStyle").value(extractTextAppearanceInformation(android.R.attr.actionButtonStyle, "QToolButton"));
-                jsonWriter.name("actionBarTabTextStyle").value(extractTextAppearanceInformation(android.R.attr.actionBarTabTextStyle, null));
-                jsonWriter.name("actionBarTabStyle").value(extractTextAppearanceInformation(android.R.attr.actionBarTabStyle, null));
-                jsonWriter.name("actionOverflowButtonStyle").value(extractImageViewInformation(android.R.attr.actionOverflowButtonStyle, null));
-                extractTabBar(jsonWriter);
-            } catch (Exception e) {
-                e.printStackTrace();
+        public SimpleJsonWriter(String filePath) throws FileNotFoundException {
+            m_writer = new OutputStreamWriter(new FileOutputStream(filePath));
+        }
+
+        public void close() throws IOException {
+            m_writer.close();
+        }
+
+        private void writeIndent() throws IOException {
+            m_writer.write(" ", 0, m_indentLevel);
+        }
+
+        void beginObject() throws IOException {
+            writeIndent();
+            m_writer.write("{\n");
+            ++m_indentLevel;
+            m_addComma = false;
+        }
+
+        void endObject() throws IOException {
+            m_writer.write("\n");
+            writeIndent();
+            m_writer.write("}\n");
+            --m_indentLevel;
+            m_addComma = false;
+        }
+
+        SimpleJsonWriter name(String name) throws IOException {
+            if (m_addComma) {
+                m_writer.write(",\n");
             }
-            jsonWriter.endObject();
-            jsonWriter.close();
+            writeIndent();
+            m_writer.write(JSONObject.quote(name) + ": ");
+            m_addComma = true;
+            return this;
         }
-        catch (Exception e) {
-            e.printStackTrace();
+
+        void value(JSONObject value) throws IOException {
+            m_writer.write(value.toString());
+        }
+    }
+
+    static class DrawableCache {
+        JSONObject object;
+        Object drawable;
+        public DrawableCache(JSONObject json, Object drawable) {
+            object = json;
+            this.drawable = drawable;
         }
     }
 }
diff --git a/src/plugins/platforms/android/extract-dummy.cpp b/src/plugins/platforms/android/extract-dummy.cpp
index bfc0dafd04..43c03792d4 100644
--- a/src/plugins/platforms/android/extract-dummy.cpp
+++ b/src/plugins/platforms/android/extract-dummy.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the plugins of the Qt Toolkit.
@@ -45,9 +45,3 @@ Java_org_qtproject_qt_android_ExtractStyle_extractNativeChunkInfo20(JNIEnv *, jo
 {
     return 0;
 }
-
-extern "C" JNIEXPORT jintArray JNICALL
-Java_org_qtproject_qt_android_ExtractStyle_extractChunkInfo20(JNIEnv *, jobject, jbyteArray)
-{
-    return 0;
-}
diff --git a/src/plugins/platforms/android/extract.cpp b/src/plugins/platforms/android/extract.cpp
index cad54d580b..4566d2ac69 100644
--- a/src/plugins/platforms/android/extract.cpp
+++ b/src/plugins/platforms/android/extract.cpp
@@ -1,5 +1,6 @@
 /****************************************************************************
 **
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Copyright (C) 2014 BogDan Vatra <bogdan@kde.org>
 ** Contact: https://www.qt.io/licensing/
 **
@@ -126,26 +127,6 @@ Java_org_qtproject_qt_android_ExtractStyle_extractNativeChunkInfo20(JNIEnv *env,
     return result;
 }
 
-extern "C" JNIEXPORT jintArray JNICALL
-Java_org_qtproject_qt_android_ExtractStyle_extractChunkInfo20(JNIEnv *env, jobject obj,
-                                                              jbyteArray chunkObj)
-{
-    size_t chunkSize = env->GetArrayLength(chunkObj);
-    void* storage = alloca(chunkSize);
-    env->GetByteArrayRegion(chunkObj, 0, chunkSize,
-                            reinterpret_cast<jbyte*>(storage));
-
-    if (QJniEnvironment::checkAndClearExceptions(env))
-        return 0;
-
-    jintArray res = Java_org_qtproject_qt_android_ExtractStyle_extractNativeChunkInfo20(env, obj,
-                                                                                    long(storage));
-    if (QJniEnvironment::checkAndClearExceptions(env))
-        res = nullptr;
-
-    return res;
-}
-
 static inline void fill9patchOffsets(Res_png_9patch20* patch) {
     patch->xDivsOffset = sizeof(Res_png_9patch20);
     patch->yDivsOffset = patch->xDivsOffset + (patch->numXDivs * sizeof(int32_t));