Add support for configurable palettes

A style's default palette is specified in qtquickcontrols2.conf in
a "Palette" group under the style's section. QSettings supports the
following two alternative syntaxes:

    [Fusion]
    Palette\Window=#dedede
    Palette\WindowText=#212121

or

    [Fusion\Palette]
    Window=#dedede
    WindowText=#212121

Change-Id: I01bf44d9e332064e955e95f619de634fcb79f010
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 83 insertions, 0 deletions

diff --git a/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc b/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc
index 1e0a1e42..358b09ce 100644
--- a/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc
+++ b/src/imports/controls/doc/src/qtquickcontrols2-configuration.qdoc
@@ -110,6 +110,89 @@
                 Available values: \c StyleNormal, \c StyleItalic, \c StyleOblique.
     \endtable
 
+    The default \l {Control::palette}{palette} can be specified in a \c Palette sub-group
+    in each style's section in the configuration file. The \c Palette sub-group can be
+    defined in two alternative ways:
+
+    \code
+    [Fusion]
+    Palette\Window=#dedede
+    Palette\WindowText=#212121
+    \endcode
+
+    or:
+    \code
+    [Fusion\Palette]
+    Window=#dedede
+    WindowText=#212121
+    \endcode
+
+    Supported palette attributes:
+    \table
+        \header
+            \li Variable
+            \li Description
+        \row
+            \li \l {QPalette::ColorRole}{\c Window}
+            \li A general background color.
+        \row
+            \li \l {QPalette::ColorRole}{\c WindowText}
+            \li A general foreground color.
+        \row
+            \li \l {QPalette::ColorRole}{\c Base}
+            \li Used mostly as the background color for text editor controls and items views.
+                It is usually white or another light color.
+        \row
+            \li \l {QPalette::ColorRole}{\c Text}
+            \li The foreground color used with \c Base. This is usually the same as the \c WindowText,
+                in which case it must provide good contrast with \c Window and \c Base.
+        \row
+            \li \l {QPalette::ColorRole}{\c Button}
+            \li The general button background color. This background can be different from \c Window
+                as some styles require a different background color for buttons.
+        \row
+            \li \l {QPalette::ColorRole}{\c ButtonText}
+            \li A foreground color used with the \c Button color.
+        \row
+            \li \l {QPalette::ColorRole}{\c BrightText}
+            \li A text color that is very different from \c WindowText, and contrasts well with e.g. \c Dark.
+                Typically used for text that needs to be drawn where \c Text, \c WindowText or \c ButtonText
+                would give poor contrast, such as on highlighted buttons.
+        \row
+            \li \l {QPalette::ColorRole}{\c ToolTipBase}
+            \li Used as the background color for tooltips.
+        \row
+            \li \l {QPalette::ColorRole}{\c ToolTipText}
+            \li Used as the foreground color for tooltips.
+
+        \row
+            \li \l {QPalette::ColorRole}{\c Light}
+            \li Lighter than \c Button.
+        \row
+            \li \l {QPalette::ColorRole}{\c Midlight}
+            \li Between \c Button and \c Light.
+        \row
+            \li \l {QPalette::ColorRole}{\c Dark}
+            \li Darker than \c Button.
+        \row
+            \li \l {QPalette::ColorRole}{\c Mid}
+            \li Between \c Button and \c Dark.
+        \row
+            \li \l {QPalette::ColorRole}{\c Shadow}
+            \li A very dark color.
+
+        \row
+            \li \l {QPalette::ColorRole}{\c Highlight}
+            \li A color to indicate a selected item or the current item.
+        \row
+            \li \l {QPalette::ColorRole}{\c HighlightedText}
+            \li A text color that contrasts with \c Highlight.
+
+        \row
+            \li \l {QPalette::ColorRole}{\c Link}
+            \li A text color used for hyperlinks.
+    \endtable
+
     In order to make it possible for Qt Quick Controls 2 to find the configuration file,
     it must be built into application's resources using the \l {The Qt Resource System}.
     Here's an example \c .qrc file: