tdf#130857 qt weld: Add QtInstanceDrawingArea basics

Add a new QtInstanceDrawingArea class as the weld::DrawingArea
implementation using native Qt widgets.

Initially only add the "basic structure" (most of the actual
functionality of drawing will be added separately):

* Add the QtInstanceDrawingArea class with most methods
currently still unimplemented and triggering an assert
when they get called.
* Add a `ScopedVclPtrInstance<VirtualDevice> m_xDevice`
member and return that in `QtInstanceDrawingArea::get_ref_device`,
as the gtk3 implementation (GtkInstanceDrawingArea) does.
* Let QtBuilder::makeObject create a QLabel for a
"GtkDrawingArea" object for now. That label will hold
a pixmap (which should be sufficient for simple cases
at least).
* Let QtInstanceBuilder::weld_drawing_area return an
instance of the new class.

Change-Id: I5d509ccd9f5a7a826a166958af4a92ff01cc0225
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/176171
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins

2 files changed, 64 insertions, 0 deletions

diff --git a/vcl/inc/qt5/QtInstanceDrawingArea.hxx b/vcl/inc/qt5/QtInstanceDrawingArea.hxx
new file mode 100644
index 000000000000..757174330c13
--- /dev/null
+++ b/vcl/inc/qt5/QtInstanceDrawingArea.hxx
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#include "QtInstanceWidget.hxx"
+
+#include <QtWidgets/QLabel>
+
+class QtInstanceDrawingArea : public QObject,
+                              public QtInstanceWidget,
+                              public virtual weld::DrawingArea
+{
+    Q_OBJECT
+
+    QLabel* m_pLabel;
+    ScopedVclPtrInstance<VirtualDevice> m_xDevice;
+
+public:
+    QtInstanceDrawingArea(QLabel* pLabel);
+
+    virtual void queue_draw() override;
+    virtual void queue_draw_area(int x, int y, int width, int height) override;
+
+    virtual void enable_drag_source(rtl::Reference<TransferDataContainer>& rTransferable,
+                                    sal_uInt8 eDNDConstants) override;
+
+    virtual void set_cursor(PointerStyle ePointerStyle) override;
+
+    virtual Point get_pointer_position() const override;
+
+    virtual void set_input_context(const InputContext& rInputContext) override;
+    virtual void im_context_set_cursor_location(const tools::Rectangle& rCursorRect,
+                                                int nExtTextInputWidth) override;
+
+    virtual OutputDevice& get_ref_device() override;
+
+    virtual a11yref get_accessible_parent() override;
+    virtual a11yrelationset get_accessible_relation_set() override;
+    virtual AbsoluteScreenPixelPoint get_accessible_location_on_screen() override;
+
+private:
+    virtual void click(const Point&) override;
+};
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/qt6/QtInstanceDrawingArea.hxx b/vcl/inc/qt6/QtInstanceDrawingArea.hxx
new file mode 100644
index 000000000000..00c19b649c0f
--- /dev/null
+++ b/vcl/inc/qt6/QtInstanceDrawingArea.hxx
@@ -0,0 +1,12 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include "../qt5/QtInstanceDrawingArea.hxx"
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */