Extend QDeclarativeImageProvider to support QPixmap loading and

synchronous loading of QImages. (QPixmaps can only be created in the
main thread so they will always be loaded synchronously).

This changes request() to requestImage() and adds requestPixmap()
for pixmap support.

Task-number: QTBUG-11989
(cherry picked from commit a258456bcb35ec4211751a702ea94a1881d82a07)

2 files changed, 39 insertions, 62 deletions

diff --git a/examples/declarative/cppextensions/imageprovider/imageprovider-example.qml b/examples/declarative/cppextensions/imageprovider/imageprovider-example.qml
index 5890c91..1ef97fa 100644
--- a/examples/declarative/cppextensions/imageprovider/imageprovider-example.qml
+++ b/examples/declarative/cppextensions/imageprovider/imageprovider-example.qml
@@ -37,29 +37,13 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-
 import Qt 4.7
-import "ImageProviderCore"
-//![0]
-ListView {
-    width: 100; height: 100
-    anchors.fill: parent
-
-    model: myModel
+import "ImageProviderCore" // import the plugin that registers the color image provider
 
-    delegate: Component {
-        Item {
-            width: 100
-            height: 50
-            Text {
-                text: "Loading..."
-                anchors.centerIn: parent
-            }
-            Image {
-                source: modelData
-                sourceSize: "50x25"
-            }
-        }
-    }
+//![0]
+Column {
+    Image { source: "image://colors/yellow" }
+    Image { source: "image://colors/red" }
 }
 //![0]
+
diff --git a/examples/declarative/cppextensions/imageprovider/imageprovider.cpp b/examples/declarative/cppextensions/imageprovider/imageprovider.cpp
index 0281b4a..995192a 100644
--- a/examples/declarative/cppextensions/imageprovider/imageprovider.cpp
+++ b/examples/declarative/cppextensions/imageprovider/imageprovider.cpp
@@ -42,7 +42,6 @@
 #include <qdeclarativeextensionplugin.h>
 
 #include <qdeclarativeengine.h>
-#include <qdeclarativecontext.h>
 #include <qdeclarative.h>
 #include <qdeclarativeitem.h>
 #include <qdeclarativeimageprovider.h>
@@ -50,62 +49,57 @@
 #include <QImage>
 #include <QPainter>
 
-/*
-   This example illustrates using a QDeclarativeImageProvider to serve
-   images asynchronously.
-*/
-
 //![0]
 class ColorImageProvider : public QDeclarativeImageProvider
 {
 public:
-    // This is run in a low priority thread.
-    QImage request(const QString &id, QSize *size, const QSize &req_size)
+    ColorImageProvider()
+        : QDeclarativeImageProvider(Pixmap)
     {
-        if (size) *size = QSize(100,50);
-        QImage image(
-                req_size.width() > 0 ? req_size.width() : 100,
-                req_size.height() > 0 ? req_size.height() : 50,
-                QImage::Format_RGB32);
-        image.fill(QColor(id).rgba());
-        QPainter p(&image);
-        QFont f = p.font();
-        f.setPixelSize(30);
-        p.setFont(f);
-        p.setPen(Qt::black);
-        if (req_size.isValid())
-            p.scale(req_size.width()/100.0, req_size.height()/50.0);
-        p.drawText(QRectF(0,0,100,50),Qt::AlignCenter,id);
-        return image;
+    }
+
+    QPixmap requestPixmap(const QString &id, QSize *size, const QSize &requestedSize)
+    {
+        int width = 100;
+        int height = 50;
+
+        if (size)
+            *size = QSize(width, height);
+        QPixmap pixmap(requestedSize.width() > 0 ? requestedSize.width() : width,
+                       requestedSize.height() > 0 ? requestedSize.height() : height); 
+        pixmap.fill(QColor(id).rgba());
+//![0]
+
+        // write the color name
+        QPainter painter(&pixmap);
+        QFont f = painter.font();
+        f.setPixelSize(20);
+        painter.setFont(f);
+        painter.setPen(Qt::black);
+        if (requestedSize.isValid())
+            painter.scale(requestedSize.width() / width, requestedSize.height() / height);
+        painter.drawText(QRectF(0, 0, width, height), Qt::AlignCenter, id);
+
+//![1]
+        return pixmap;
     }
 };
+//![1]
 
 
 class ImageProviderExtensionPlugin : public QDeclarativeExtensionPlugin
 {
     Q_OBJECT
 public:
-    void registerTypes(const char *uri) {
+    void registerTypes(const char *uri)
+    {
         Q_UNUSED(uri);
-
     }
 
-    void initializeEngine(QDeclarativeEngine *engine, const char *uri) {
+    void initializeEngine(QDeclarativeEngine *engine, const char *uri)
+    {
         Q_UNUSED(uri);
-
         engine->addImageProvider("colors", new ColorImageProvider);
-
-        QStringList dataList;
-        dataList.append("image://colors/red");
-        dataList.append("image://colors/green");
-        dataList.append("image://colors/blue");
-        dataList.append("image://colors/brown");
-        dataList.append("image://colors/orange");
-        dataList.append("image://colors/purple");
-        dataList.append("image://colors/yellow");
-
-        QDeclarativeContext *ctxt = engine->rootContext();
-        ctxt->setContextProperty("myModel", QVariant::fromValue(dataList));
     }
 
 };
@@ -113,5 +107,4 @@ public:
 #include "imageprovider.moc"
 
 Q_EXPORT_PLUGIN(ImageProviderExtensionPlugin);
-//![0]