Introduce new mechanism to manage palette functionality in QML

Main goals of these changes:
1) Add an ability to work with disabled and inactive palettes from QML
2) Eliminate massive code duplication in qtquickcontrols2 module
3) Provide easily extensible architecture for this piece of
functionality

Architectural part.

Palette
It was decided to not change existing QPalette, but add thin wrappers
around it to provide all required functionality. These wrappers are
highly coupled with QPalette class because of using some enum values
from it.
There are two new classes QQuickPalette and QQuickColorGroup.
QQuickPalette class inherits QQuickColorGroup class and represents
Active/All color group. QQuickPalette also provides an access to three
color groups: Active, Inactive, and Disabled.
In order to access colors the special class QQuickPaletteColorProvider
is used. This is a wrapper around QPalette that provides some
convenience functions.

Interface
The private property "palette" should be exposed.

Implementation
All private parts of classes that implement
QQuickAbstractPaletteProvider have to inherit
QQuickPaletteProviderPrivateBase class. This template class implement
all functionality: create palette, resolve dependencies, connect objects
etc. This is important to mention that related data is lazily
allocatable on demand only. Hence, there is no memory overhead for
regular items.

Change-Id: I911424b730451b1ad47f68fd8007953b66eddb28
Reviewed-by: Volker Hilsheimer <[email protected]>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/quick/items/qquickwindow.h b/src/quick/items/qquickwindow.h
index bba8c014c8..1331d036e1 100644
--- a/src/quick/items/qquickwindow.h
+++ b/src/quick/items/qquickwindow.h
@@ -224,6 +224,9 @@ Q_SIGNALS:
     Q_REVISION(2, 14) void beforeRenderPassRecording();
     Q_REVISION(2, 14) void afterRenderPassRecording();
 
+    Q_REVISION(6, 0) void paletteChanged();
+    Q_REVISION(6, 0) void paletteCreated();
+
 public Q_SLOTS:
     void update();
     void releaseResources();