Android selection handles

This commits implement the cursor and selection handle in the platform
plugin.

Task-number: QTBUG-34867
Change-Id: Icb3fd9ddfd9f4152e2004078a92a3d9502e9113c
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

3 files changed, 273 insertions, 0 deletions

diff --git a/src/android/jar/src/org/qtproject/qt5/android/CursorHandle.java b/src/android/jar/src/org/qtproject/qt5/android/CursorHandle.java
new file mode 100644
index 0000000000..7d26b8fa04
--- /dev/null
+++ b/src/android/jar/src/org/qtproject/qt5/android/CursorHandle.java
@@ -0,0 +1,205 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 Olivier Goffart <ogoffart@woboq.com>
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Android port of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+package org.qtproject.qt5.android;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.util.DisplayMetrics;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.LinearLayout;
+import android.widget.ImageView;
+import android.content.res.TypedArray;
+import android.graphics.drawable.Drawable;
+import android.view.MotionEvent;
+import android.widget.PopupWindow;
+import android.app.Activity;
+import android.view.ViewTreeObserver;
+
+/* This view represents one of the handle (selection or cursor handle) */
+class CursorView extends ImageView
+{
+    private CursorHandle mHandle;
+    // The coordinare which where clicked
+    private int m_offsetX;
+    private int m_offsetY;
+
+    CursorView (Context context, CursorHandle handle) {
+        super(context);
+        mHandle = handle;
+    }
+
+    // Called when the handle was moved programatically , with the delta amount in pixels
+    public void adjusted(int dx, int dy) {
+        m_offsetX += dx;
+        m_offsetY += dy;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent ev) {
+        switch (ev.getActionMasked()) {
+        case MotionEvent.ACTION_DOWN: {
+            m_offsetX = Math.round(ev.getRawX());
+            m_offsetY = Math.round(ev.getRawY());
+            break;
+        }
+
+        case MotionEvent.ACTION_MOVE: {
+            mHandle.updatePosition(Math.round(ev.getRawX()) - m_offsetX,
+                                    Math.round(ev.getRawY()) - m_offsetY);
+            break;
+        }
+
+        case MotionEvent.ACTION_UP:
+            break;
+
+        case MotionEvent.ACTION_CANCEL:
+            break;
+        }
+        return true;
+    }
+
+}
+
+// Helper class that manages a cursor or selection handle
+public class CursorHandle implements ViewTreeObserver.OnPreDrawListener
+{
+    private View m_layout = null;
+    private CursorView m_cursorView = null;
+    private PopupWindow m_popup = null;
+    private int m_id;
+    private int m_attr;
+    private Activity m_activity;
+    private int m_posX;
+    private int m_posY;
+    private int m_lastX;
+    private int m_lastY;
+    int tolerance;
+
+    public CursorHandle(Activity activity, View layout, int id, int attr) {
+        m_activity = activity;
+        m_id = id;
+        m_attr = attr;
+        m_layout = layout;
+        DisplayMetrics metrics = new DisplayMetrics();
+        activity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
+        tolerance = Math.round(2 * metrics.density);
+        m_lastX = m_lastY = -1 - tolerance;
+    }
+
+    private boolean initOverlay(){
+        if (m_popup == null){
+
+            Context context = m_layout.getContext();
+            int[] attrs = {m_attr};
+            TypedArray a = context.getTheme().obtainStyledAttributes(attrs);
+            Drawable drawable = a.getDrawable(0);
+
+            m_cursorView = new CursorView(context, this);
+            m_cursorView.setImageDrawable(drawable);
+            // m_layout.addView(m_cursorView);
+
+            m_popup = new PopupWindow(context, null, android.R.attr.textSelectHandleWindowStyle);
+            m_popup.setSplitTouchEnabled(true);
+            m_popup.setClippingEnabled(false);
+            m_popup.setContentView(m_cursorView);
+            m_popup.setWidth(drawable.getIntrinsicWidth());
+            m_popup.setHeight(drawable.getIntrinsicHeight());
+
+            m_layout.getViewTreeObserver().addOnPreDrawListener(this);
+        }
+        return true;
+    }
+
+    // Show the handle at a given position (or move it if it is already shown)
+    public void setPosition(final int x, final int y){
+        initOverlay();
+
+        final int[] location = new int[2];
+        m_layout.getLocationOnScreen(location);
+
+        int x2 = x + location[0];
+        int y2 = y + location[1];
+
+        if (m_id == QtNative.IdCursorHandle) {
+            x2 -= m_cursorView.getWidth() / 2 ;
+        } else if (m_id == QtNative.IdLeftHandle) {
+            x2 -= m_cursorView.getWidth() * 3 / 4;
+        } else if (m_id == QtNative.IdRightHandle) {
+            x2 -= m_cursorView.getWidth() / 4;
+        }
+
+        if (m_popup.isShowing()) {
+            m_popup.update(x2, y2, -1, -1);
+            m_cursorView.adjusted(x - m_posX, y - m_posY);
+        } else {
+            m_popup.showAtLocation(m_layout, 0, x2, y2);
+        }
+
+        m_posX = x;
+        m_posY = y;
+    }
+
+    public void hide() {
+        if (m_popup != null) {
+            m_popup.dismiss();
+        }
+    }
+
+    // The handle was dragged by a given relative position
+    public void updatePosition(int x, int y) {
+        if (Math.abs(m_lastX - x) > tolerance || Math.abs(m_lastY - y) > tolerance) {
+            QtNative.handleLocationChanged(m_id, x + m_posX, y + m_posY);
+            m_lastX = x;
+            m_lastY = y;
+        }
+    }
+
+    @Override
+    public boolean onPreDraw() {
+        // This hook is called when the view location is changed
+        // For example if the keyboard appears.
+        // Adjust the position of the handle accordingly
+        if (m_popup != null && m_popup.isShowing())
+            setPosition(m_posX, m_posY);
+
+        return true;
+    }
+}
diff --git a/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java b/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java
index 656dbdda45..55de75e991 100644
--- a/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java
+++ b/src/android/jar/src/org/qtproject/qt5/android/QtActivityDelegate.java
@@ -2,6 +2,7 @@
 **
 ** Copyright (C) 2014 BogDan Vatra <bogdan@kde.org>
 ** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2016 Olivier Goffart <ogoffart@woboq.com>
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the Android port of the Qt Toolkit.
@@ -143,6 +144,9 @@ public class QtActivityDelegate
     private int m_portraitKeyboardHeight = 0;
     private int m_landscapeKeyboardHeight = 0;
     private int m_probeKeyboardHeightDelay = 50; // ms
+    private CursorHandle m_cursorHandle;
+    private CursorHandle m_leftSelectionHandle;
+    private CursorHandle m_rightSelectionHandle;
 
     public void setFullScreen(boolean enterFullScreen)
     {
@@ -470,6 +474,49 @@ public class QtActivityDelegate
         m_imm.updateSelection(m_editText, selStart, selEnd, candidatesStart, candidatesEnd);
     }
 
+    // Values coming from QAndroidInputContext::CursorHandleShowMode
+    private static final int CursorHandleNotShown = 0;
+    private static final int CursorHandleShowNormal = 1;
+    private static final int CursorHandleShowSelection = 2;
+
+    /* called from the C++ code when the position of the cursor or selection handles needs to
+       be adjusted
+
+       mode is one of QAndroidInputContext::CursorHandleShowMode)
+    */
+    public void updateHandles(int mode, int x1, int y1, int x2, int y2)
+    {
+        if (mode == CursorHandleNotShown) {
+            if (m_cursorHandle != null)
+                m_cursorHandle.hide();
+            if (m_rightSelectionHandle != null) {
+                m_rightSelectionHandle.hide();
+                m_leftSelectionHandle.hide();
+            }
+        } else if (mode == CursorHandleShowNormal) {
+            if (m_cursorHandle == null) {
+                m_cursorHandle = new CursorHandle(m_activity, m_layout, QtNative.IdCursorHandle,
+                                                  android.R.attr.textSelectHandle);
+            }
+            m_cursorHandle.setPosition(x1, y1);
+            if (m_rightSelectionHandle != null) {
+                m_rightSelectionHandle.hide();
+                m_leftSelectionHandle.hide();
+            }
+        } else if (mode == CursorHandleShowSelection) {
+            if (m_rightSelectionHandle == null) {
+                m_leftSelectionHandle = new CursorHandle(m_activity, m_layout, QtNative.IdLeftHandle,
+                                                         android.R.attr.textSelectHandleLeft);
+                m_rightSelectionHandle = new CursorHandle(m_activity, m_layout, QtNative.IdRightHandle,
+                                                          android.R.attr.textSelectHandleRight);
+            }
+            m_leftSelectionHandle.setPosition(x1,y1);
+            m_rightSelectionHandle.setPosition(x2,y2);
+            if (m_cursorHandle != null)
+                m_cursorHandle.hide();
+        }
+    }
+
     public boolean loadApplication(Activity activity, ClassLoader classLoader, Bundle loaderParams)
     {
         /// check parameters integrity
diff --git a/src/android/jar/src/org/qtproject/qt5/android/QtNative.java b/src/android/jar/src/org/qtproject/qt5/android/QtNative.java
index 04b8e6a06f..6f4b0503d5 100644
--- a/src/android/jar/src/org/qtproject/qt5/android/QtNative.java
+++ b/src/android/jar/src/org/qtproject/qt5/android/QtNative.java
@@ -492,6 +492,20 @@ public class QtNative
         });
     }
 
+    private static void updateHandles(final int mode,
+                                      final int x1,
+                                      final int y1,
+                                      final int x2,
+                                      final int y2)
+    {
+        runAction(new Runnable() {
+            @Override
+            public void run() {
+                m_activityDelegate.updateHandles(mode, x1, y1, x2, y2);
+            }
+        });
+    }
+
     private static void showSoftwareKeyboard(final int x,
                                              final int y,
                                              final int width,
@@ -777,6 +791,13 @@ public class QtNative
     public static native void keyboardGeometryChanged(int x, int y, int width, int height);
     // keyboard methods
 
+    // handle methods
+    public static final int IdCursorHandle = 1;
+    public static final int IdLeftHandle = 2;
+    public static final int IdRightHandle = 3;
+    public static native void handleLocationChanged(int id, int x, int y);
+    // handle methods
+
     // dispatch events methods
     public static native boolean dispatchGenericMotionEvent(MotionEvent ev);
     public static native boolean dispatchKeyEvent(KeyEvent event);