Read shader files from qml

Move reading of shader files from c++ to qml.

Change-Id: I60bd958f58b3e152187989a1429289fd364f8cc2
Reviewed-by: Lasse Räihä <lasse.raiha@digia.com>

5 files changed, 28 insertions, 48 deletions

diff --git a/QtDemo/QtDemo.pro b/QtDemo/QtDemo.pro
index 3c376ff..b4c175d 100644
--- a/QtDemo/QtDemo.pro
+++ b/QtDemo/QtDemo.pro
@@ -2,10 +2,7 @@ TEMPLATE = app
 
 QT += qml quick xmlpatterns sql svg multimedia
 
-HEADERS += shaderfilereader.h
-
-SOURCES += main.cpp \
-           shaderfilereader.cpp
+SOURCES += main.cpp
 
 RESOURCES += qml.qrc
 
diff --git a/QtDemo/main.cpp b/QtDemo/main.cpp
index 5accb61..e3572ea 100644
--- a/QtDemo/main.cpp
+++ b/QtDemo/main.cpp
@@ -1,16 +1,12 @@
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
 #include <QQmlContext>
-#include "shaderfilereader.h"
 
 int main(int argc, char *argv[])
 {
     QGuiApplication app(argc, argv);
 
-    ShaderFileReader fileReader;
-
     QQmlApplicationEngine engine;
-    engine.rootContext()->setContextProperty("shaderFileReader", &fileReader);
     engine.load(QUrl(QStringLiteral("qrc:///qml/QtDemo/main.qml")));
 
     return app.exec();
diff --git a/QtDemo/qml/QtDemo/demos/shaders/Effects/Effect.qml b/QtDemo/qml/QtDemo/demos/shaders/Effects/Effect.qml
index 5ec282c..872540e 100755
--- a/QtDemo/qml/QtDemo/demos/shaders/Effects/Effect.qml
+++ b/QtDemo/qml/QtDemo/demos/shaders/Effects/Effect.qml
@@ -42,6 +42,7 @@
 import QtQuick 2.2
 
 ShaderEffect {
+    id: shaderEffect
     property variant source
     property ListModel parameters: ListModel { }
     property bool divider: false
@@ -65,11 +66,31 @@ ShaderEffect {
     }
 
     // The following is a workaround for the fact that ShaderEffect
-    // doesn't provide a way for shader programs to be read from a file,
-    // rather than being inline in the QML file
+    // doesn't provide a way for shader programs to be read from a file.
+    QtObject {
+        id: shaderFileReader
+
+        signal fileReady(string shader, string shaderType)
+
+        function readFile(shaderFile, shaderType)
+        {
+            var xhr = new XMLHttpRequest
+            xhr.open("GET", "../" + shaderFile, true)
+            xhr.onreadystatechange = function() {
+                if (xhr.readyState == XMLHttpRequest.DONE)
+                    shaderFileReader.fileReady(xhr.responseText, shaderType)
+            }
+            xhr.send()
+        }
+
+        onFileReady: {
+            if (shaderType == "fragment")
+                shaderEffect.fragmentShader = d.fragmentShaderCommon + shader
+            if (shaderType == "vertex")
+                shaderEffect.vertexShader = shader
+        }
+    }
 
-    onFragmentShaderFilenameChanged:
-        fragmentShader = d.fragmentShaderCommon + shaderFileReader.readFile("qml/QtDemo/demos/shaders/" + fragmentShaderFilename)
-    onVertexShaderFilenameChanged:
-        vertexShader = shaderFileReader.readFile("qml/QtDemo/demos/shaders/" + vertexShaderFilename)
+    onFragmentShaderFilenameChanged: shaderFileReader.readFile(fragmentShaderFilename, "fragment")
+    onVertexShaderFilenameChanged: shaderFileReader.readFile(vertexShaderFilename, "vertex")
 }
diff --git a/QtDemo/shaderfilereader.cpp b/QtDemo/shaderfilereader.cpp
deleted file mode 100644
index e394682..0000000
--- a/QtDemo/shaderfilereader.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-#include "shaderfilereader.h"
-#include <QtCore/QDir>
-#include <QtCore/QFile>
-#include <QtCore/QFileInfo>
-#include <QtCore/QTextStream>
-#include <QtCore/QDebug>
-
-QString ShaderFileReader::readFile(const QString &fileName)
-{
-    QString content;
-    QFile file(QString(QStringLiteral(":/%1")).arg(fileName));
-
-    if (file.open(QIODevice::ReadOnly)) {
-        QTextStream stream(&file);
-        content = stream.readAll();
-        file.close();
-    }
-    return content;
-}
-
diff --git a/QtDemo/shaderfilereader.h b/QtDemo/shaderfilereader.h
deleted file mode 100644
index 74b7779..0000000
--- a/QtDemo/shaderfilereader.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#ifndef SHADERFILEREADER_H
-#define SHADERFILEREADER_H
-
-#include <QObject>
-
-class ShaderFileReader : public QObject
-{
-    Q_OBJECT
-
-public:
-    Q_INVOKABLE QString readFile(const QString &fileName);
-};
-
-#endif // SHADERFILEREADER_H