Add devicePixelRatio support to the Windows QPA plugin.

This adds support for the environment variable
QT_DEVICE_PIXEL_RATIO for the Windows platform plugin.

Task-number: QTBUG-38993
Task-number: QTBUG-38858
Change-Id: I6831eb6d3a09a80be7bbef46395e91531b61cc50
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>
tst_qtreeview: Skip test that crashes on Wayland.

Change-Id: Iff2499dff1906a7c65fc5c007b96675f4bac2b42
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
tst_qtreewidget: Skip test that crashes on Wayland.

Change-Id: I6cc2eb90df57eb5c33d3a93920ea719b5e2cfc0d
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
fix a camel case include guard macro

Change-Id: I502ecf6c862f101e426536e11f5c466ed3419946
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
QDataWidgetMapper: micro-optimize handling of the widget map

Don't use index-based iteration, but use iterators.

Change-Id: I57c9582aed644fc58ced1a1af940dcd20d11d970
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
QDataWidgetMapper: micro-optimize clearMapping()

QList<WidgetMapper>::takeLast() is a needlessly expensive operation
(involves copying a QPersistentModelIndex and a QPointer).

Instead of looping over takeLast() until empty, reverse-iterate
over the list and call removeEventFilter(), then clear the whole
list.

We reverse-iterate to preserve existing behavior. Also, since the
original code popped the WidgetMapper instance before calling
removeEventFilter(), we move the whole list into a local copy
before iterating. There's little chance that a removeEventFilter()
call will cause reentrancy into QDataWidgetMapper, but better safe
than sorry.

This and the previous change together save 448 bytes of text size in
libQt5Widgets.

Change-Id: I1bfe907751659f31e618aa05bbb7b840f0aa61f4
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Remove unused variable

Change-Id: I0414d7bab89371f330d5b0cfa88758e3f1668f32
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>
Remove QAccessibleToolButton::text

This function actually is worse than just calling
QAccessibleButton::text which it already does. It would mess up the
shortcut handling in addition to that.

Change-Id: I56cb95a44624da4c5fccb43e6835f6012a083337
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>
Clean up QAccessibleTabBar

Change-Id: Ic0949e4d76a7332ef1a42c93a06a0e4515c1192d
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>
Accessibility iOS: Fix crash after deleting a view

Change-Id: I64e8357fcbf7f312308490351b7c692d31db5a43
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>
Mention supportedMimeTypes() in QImageReader documentation.

Change-Id: Iaa07a463e07982352fe2c7dd77d691a390a65f35
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Document loading of high resolution versions of images.

Task-number: QTBUG-38858
Change-Id: I87ee18b66e137f5f5c01d77910f1a7f256b85e18
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>