vcl: implement rotate gesture infrastructure

This change implements internal infrastructure to pass rotate gestures
from low-level sources to the consuming GUI widgets. The API follows the
established begin-update-update-...-end event convention that is used on
various platforms.

The API should be enough to support bouth touchpad and touchscreen
gestures, as long as the underlying low-level source exposes enough
information. The hardware drivers usually expose touchpad gestures
already recognized whereas touchscreen gestures come as a set of moving
touchpoints and application needs to figure out their meaning itself.
Many toolkits recognize both and offer a unified higher-level interface
that can be used by us.

Change-Id: Iae667b3248d6f78bfb1eef755af6bc996432b6a7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/138788
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

5 files changed, 119 insertions, 0 deletions

diff --git a/include/vcl/GestureEventRotate.hxx b/include/vcl/GestureEventRotate.hxx
new file mode 100644
index 000000000000..39f4b310f973
--- /dev/null
+++ b/include/vcl/GestureEventRotate.hxx
@@ -0,0 +1,46 @@
+/* -*- 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 <vcl/dllapi.h>
+
+enum class GestureEventRotateType
+{
+    Begin,
+    Update,
+    End
+};
+
+class VCL_DLLPUBLIC GestureEventRotate
+{
+public:
+    sal_Int32 mnX = 0;
+    sal_Int32 mnY = 0;
+
+    GestureEventRotateType meEventType = GestureEventRotateType::Begin;
+
+    // The difference of between the current gesture scale and the scale at the beginning of the
+    // gesture.
+    double mfAngleDelta = 0;
+
+    GestureEventRotate() = default;
+
+    GestureEventRotate(sal_Int32 nInitialX, sal_Int32 nInitialY, GestureEventRotateType eEventType,
+                       double fAngleDelta)
+        : mnX(nInitialX)
+        , mnY(nInitialY)
+        , meEventType(eEventType)
+        , mfAngleDelta(fAngleDelta)
+    {
+    }
+};
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/include/vcl/commandevent.hxx b/include/vcl/commandevent.hxx
index 71694cc6f087..7b3199b18ccd 100644
--- a/include/vcl/commandevent.hxx
+++ b/include/vcl/commandevent.hxx
@@ -29,6 +29,7 @@
 #include <rtl/ustring.hxx>
 #include <vcl/GestureEvent.hxx>
 #include <vcl/GestureEventZoom.hxx>
+#include <vcl/GestureEventRotate.hxx>
 
 class CommandExtTextInputData;
 class CommandWheelData;
@@ -41,6 +42,7 @@ class CommandSwipeData;
 class CommandLongPressData;
 class CommandGestureData;
 class CommandGestureZoomData;
+class CommandGestureRotateData;
 
 enum class CommandEventId;
 
@@ -93,6 +95,7 @@ public:
     const CommandLongPressData*         GetLongPressData() const;
     const CommandGestureData*           GetGestureData() const;
     const CommandGestureZoomData*       GetGestureZoomData() const;
+    const CommandGestureRotateData*     GetGestureRotateData() const;
 };
 
 class VCL_DLLPUBLIC CommandExtTextInputData
@@ -341,6 +344,23 @@ public:
     {}
 };
 
+class VCL_DLLPUBLIC CommandGestureRotateData
+{
+public:
+    const double mfX = 0;
+    const double mfY = 0;
+    const GestureEventRotateType meEventType = GestureEventRotateType::Begin;
+    const double mfAngleDelta = 0;
+
+    CommandGestureRotateData(double fX, double fY, GestureEventRotateType eEventType,
+                             double fAngleDelta)
+        : mfX(fX)
+        , mfY(fY)
+        , meEventType(eEventType)
+        , mfAngleDelta(fAngleDelta)
+    {}
+};
+
 enum class CommandEventId
 {
     NONE                    = 0,
@@ -366,6 +386,7 @@ enum class CommandEventId
     LongPress               = 22,
     Gesture                 = 23,
     GestureZoom             = 24,
+    GestureRotate           = 25,
 };
 
 #endif // INCLUDED_VCL_COMMANDEVENT_HXX
diff --git a/vcl/inc/salwtype.hxx b/vcl/inc/salwtype.hxx
index d920a16dc5d4..7b66ef5a2d45 100644
--- a/vcl/inc/salwtype.hxx
+++ b/vcl/inc/salwtype.hxx
@@ -27,6 +27,7 @@
 #include <tools/long.hxx>
 #include <vcl/GestureEvent.hxx>
 #include <vcl/GestureEventZoom.hxx>
+#include <vcl/GestureEventRotate.hxx>
 
 class LogicalFontInstance;
 class SalGraphics;
@@ -93,6 +94,7 @@ enum class SalEvent {
     ExternalGesture,
     Gesture,
     GestureZoom,
+    GestureRotate,
 };
 
 struct SalAbstractMouseEvent
@@ -273,6 +275,14 @@ struct SalGestureZoomEvent
     double mfScaleDelta = 0;
 };
 
+struct SalGestureRotateEvent
+{
+    GestureEventRotateType meEventType = GestureEventRotateType::Begin;
+    tools::Long mnX = 0;
+    tools::Long mnY = 0;
+    double mfAngleDelta = 0;
+};
+
 typedef void (*SALTIMERPROC)();
 
 #endif // INCLUDED_VCL_INC_SALWTYPE_HXX
diff --git a/vcl/source/window/commandevent.cxx b/vcl/source/window/commandevent.cxx
index aeedcc79c197..5fdb5e9e41a1 100644
--- a/vcl/source/window/commandevent.cxx
+++ b/vcl/source/window/commandevent.cxx
@@ -203,5 +203,12 @@ const CommandGestureZoomData* CommandEvent::GetGestureZoomData() const
         return nullptr;
 }
 
+const CommandGestureRotateData* CommandEvent::GetGestureRotateData() const
+{
+    if (mnCommand == CommandEventId::GestureRotate)
+        return static_cast<const CommandGestureRotateData*>(mpData);
+    else
+        return nullptr;
+}
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/window/winproc.cxx b/vcl/source/window/winproc.cxx
index 945cae89e76e..d98b8c2fae42 100644
--- a/vcl/source/window/winproc.cxx
+++ b/vcl/source/window/winproc.cxx
@@ -33,6 +33,7 @@
 #include <vcl/event.hxx>
 #include <vcl/GestureEvent.hxx>
 #include <vcl/GestureEventZoom.hxx>
+#include <vcl/GestureEventRotate.hxx>
 #include <vcl/settings.hxx>
 #include <vcl/svapp.hxx>
 #include <vcl/cursor.hxx>
@@ -1848,6 +1849,34 @@ static bool ImplHandleGestureZoomEvent(vcl::Window* pWindow, const SalGestureZoo
     return aHandler.HandleEvent();
 }
 
+namespace {
+
+class HandleGestureRotateEvent : public HandleGestureEvent
+{
+private:
+    CommandGestureRotateData m_aGestureData;
+
+public:
+    HandleGestureRotateEvent(vcl::Window* pWindow, const SalGestureRotateEvent& rEvent)
+        : HandleGestureEvent(pWindow, Point(rEvent.mnX, rEvent.mnY))
+        , m_aGestureData(rEvent.mnX, rEvent.mnY, rEvent.meEventType, rEvent.mfAngleDelta)
+    {
+    }
+
+    virtual bool CallCommand(vcl::Window* pWindow, const Point& /*rMousePos*/) override
+    {
+        return ImplCallCommand(pWindow, CommandEventId::GestureRotate, &m_aGestureData);
+    }
+};
+
+}
+
+static bool ImplHandleGestureRotateEvent(vcl::Window* pWindow, const SalGestureRotateEvent& rEvent)
+{
+    HandleGestureRotateEvent aHandler(pWindow, rEvent);
+    return aHandler.HandleEvent();
+}
+
 static void ImplHandlePaint( vcl::Window* pWindow, const tools::Rectangle& rBoundRect, bool bImmediateUpdate )
 {
     // system paint events must be checked for re-mirroring
@@ -2908,6 +2937,12 @@ bool ImplWindowFrameProc( vcl::Window* _pWindow, SalEvent nEvent, const void* pE
             bRet = ImplHandleGestureZoomEvent(pWindow, *pGestureEvent);
         }
         break;
+        case SalEvent::GestureRotate:
+        {
+            const auto * pGestureEvent = static_cast<SalGestureRotateEvent const *>(pEvent);
+            bRet = ImplHandleGestureRotateEvent(pWindow, *pGestureEvent);
+        }
+        break;
         default:
             SAL_WARN( "vcl.layout", "ImplWindowFrameProc(): unknown event (" << static_cast<int>(nEvent) << ")" );
             break;