Improve Touch support

With this patch dolphin now supports the following touch gestures:

* Tap gesture to interact/open with directories, files and so on
* TapAndHold and release gesture for access to the context menu (main window, panel folder, places and information)
* TapAndHold and moving gesture for drag and drop action (main windows, panel folder and places)
* pinch gesture for zoom in main window
* kinetic scrolling (QScroller) for main window, panel folder, panel places, panel information, setting preview and service
* two fingers swipe gesture to left, right and up as shortcut to navigate back, forward and up
* two finger tap gesture to toggle item selection, similar to Ctrl and left mouse click

FEATURE: 385066
FIXED-IN: 20.11.80

 You are currently rebasing branch 'touch' on '85241a924'.

3 files changed, 39 insertions, 0 deletions

diff --git a/src/panels/information/informationpanel.cpp b/src/panels/information/informationpanel.cpp
index 5f4ac84e8..f843e7f46 100644
--- a/src/panels/information/informationpanel.cpp
+++ b/src/panels/information/informationpanel.cpp
@@ -405,6 +405,7 @@ void InformationPanel::init()
     m_content = new InformationPanelContent(this);
     connect(m_content, &InformationPanelContent::urlActivated, this, &InformationPanel::urlActivated);
     connect(m_content, &InformationPanelContent::configurationFinished, this, [this]() { m_inConfigurationMode = false; });
+    connect(m_content, &InformationPanelContent::contextMenuRequested, this, &InformationPanel::showContextMenu);
 
     QVBoxLayout* layout = new QVBoxLayout(this);
     layout->setContentsMargins(0, 0, 0, 0);
diff --git a/src/panels/information/informationpanelcontent.cpp b/src/panels/information/informationpanelcontent.cpp
index d632cfcd1..ded88bd96 100644
--- a/src/panels/information/informationpanelcontent.cpp
+++ b/src/panels/information/informationpanelcontent.cpp
@@ -33,11 +33,13 @@
 #include <QTextLayout>
 #include <QTimer>
 #include <QVBoxLayout>
+#include <QScroller>
 #include <QStyle>
 #include <QPainter>
 #include <QBitmap>
 #include <QLinearGradient>
 #include <QPolygon>
+#include <QGesture>
 
 #include "dolphin_informationpanelsettings.h"
 #include "phononwidget.h"
@@ -134,6 +136,7 @@ InformationPanelContent::InformationPanelContent(QWidget* parent) :
     m_metaDataArea->setFrameShape(QFrame::NoFrame);
 
     QWidget* viewport = m_metaDataArea->viewport();
+    QScroller::grabGesture(viewport, QScroller::TouchGesture);
     viewport->installEventFilter(this);
 
     layout->addWidget(m_preview);
@@ -144,6 +147,8 @@ InformationPanelContent::InformationPanelContent(QWidget* parent) :
     layout->addWidget(m_metaDataArea);
     layout->addWidget(m_configureButtons);
 
+    grabGesture(Qt::TapAndHoldGesture);
+
     m_placesItemModel = new PlacesItemModel(this);
 }
 
@@ -338,6 +343,33 @@ bool InformationPanelContent::eventFilter(QObject* obj, QEvent* event)
     return QWidget::eventFilter(obj, event);
 }
 
+bool InformationPanelContent::event(QEvent* event)
+{
+    if (event->type() == QEvent::Gesture) {
+        gestureEvent(static_cast<QGestureEvent*>(event));
+        return true;
+    }
+    return QWidget::event(event);
+}
+
+bool InformationPanelContent::gestureEvent(QGestureEvent* event)
+{
+    if (!underMouse()) {
+        return false;
+    }
+
+    QTapAndHoldGesture* tap = static_cast<QTapAndHoldGesture*>(event->gesture(Qt::TapAndHoldGesture));
+
+    if (tap) {
+        if (tap->state() == Qt::GestureFinished) {
+            emit contextMenuRequested(tap->position().toPoint());
+        }
+        event->accept();
+        return true;
+    }
+    return false;
+}
+
 void InformationPanelContent::showIcon(const KFileItem& item)
 {
     m_outdatedPreviewTimer->stop();
diff --git a/src/panels/information/informationpanelcontent.h b/src/panels/information/informationpanelcontent.h
index 7b83e5d41..abdfdeb35 100644
--- a/src/panels/information/informationpanelcontent.h
+++ b/src/panels/information/informationpanelcontent.h
@@ -23,6 +23,7 @@ class QDialogButtonBox;
 class QString;
 class QLabel;
 class QScrollArea;
+class QGestureEvent;
 
 namespace KIO {
   class PreviewJob;
@@ -78,6 +79,7 @@ public:
 signals:
     void urlActivated( const QUrl& url );
     void configurationFinished();
+    void contextMenuRequested(const QPoint& pos);
 
 public slots:
     /**
@@ -90,6 +92,8 @@ protected:
     /** @see QObject::eventFilter() */
     bool eventFilter(QObject* obj, QEvent* event) override;
 
+    bool event(QEvent * event) override;
+
 private slots:
     /**
      * Is invoked if no preview is available for the item. In this
@@ -131,6 +135,8 @@ private:
      */
     void refreshPixmapView();
 
+    bool gestureEvent(QGestureEvent* event);
+
 private:
     KFileItem m_item;