Merge pull request #43 from vSLG/trackpad

Add option to disable kinetic scrolling

src/backend/user_files.py

@@ -235,6 +235,7 @@ class UISettings(JSONDataFile):
             "clearRoomFilterOnEscape": True,
             "clearMemberFilterOnEscape": True,
             "collapseSidePanesUnderWindowWidth": 400,
+            "enableKineticScrolling": True,
             "hideProfileChangeEvents": True,
             "hideMembershipEvents": False,
             "hideUnknownEvents": False,

src/gui/Base/HFlickable.qml

@@ -5,5 +5,7 @@ import QtQuick.Controls 2.12
 
 Flickable {
     interactive: contentWidth > width || contentHeight > height
-    ScrollBar.vertical: ScrollBar {}
+    ScrollBar.vertical: ScrollBar {
+        visible: parent.interactive
+    }
 }

src/gui/Base/HFlickableColumnPage.qml

@@ -26,4 +26,9 @@ HPage {
             height: flickable.height
         }
     }
+
+    HKineticScrollingDisabler {
+        flickable: flickable
+        anchors.fill: flickable
+    }
 }

src/gui/Base/HGridView.qml

@@ -5,7 +5,6 @@ import QtQuick.Controls 2.12
 
 GridView {
     id: gridView
-    interactive: allowDragging
     currentIndex: -1
     keyNavigationWraps: true
     highlightMoveDuration: theme.animationDuration
@@ -23,7 +22,7 @@ GridView {
     }
 
     ScrollBar.vertical: ScrollBar {
-        visible: gridView.interactive || ! gridView.allowDragging
+        visible: gridView.interactive
     }
 
     // property bool debug: false
@@ -59,7 +58,6 @@ GridView {
     onSelectedCountChanged: if (! selectedCount) lastCheckedDelegateIndex = 0
 
 
-    property bool allowDragging: true
     property alias cursorShape: mouseArea.cursorShape
     property int currentItemHeight: currentItem ? currentItem.height : 0
 
@@ -119,22 +117,8 @@ GridView {
     }
 
 
-    Connections {
+    HKineticScrollingDisabler {
-        target: gridView
-        enabled: ! gridView.allowDragging
-        // interactive gets temporarily set to true below to allow wheel scroll
-        onDraggingChanged: gridView.interactive = false
-    }
-
-    MouseArea {
         id: mouseArea
         anchors.fill: parent
-        enabled: ! parent.allowDragging || cursorShape !== Qt.ArrowCursor
-        acceptedButtons: Qt.NoButton
-        onWheel: {
-            // Allow wheel usage, will be back to false on any drag attempt
-            parent.interactive = true
-            wheel.accepted = false
-        }
     }
 }

src/gui/Base/HKineticScrollingDisabler.qml

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+import QtQuick 2.12
+
+// MouseArea component to disable kinetic scrolling
+MouseArea {
+    id: mouseArea
+    enabled: ! window.settings.enableKineticScrolling
+    propagateComposedEvents: true
+    acceptedButtons: Qt.NoButton
+
+
+    onWheel: {
+        // Make components below the stack notice the wheel event
+        wheel.accepted = false
+
+        const pos = getNewPosition(flickable, wheel)
+        flickable.flick(0, 0)
+        flickable.contentY = pos
+    }
+
+
+    property Flickable flickable: parent
+
+    // Used to get default flickDeceleration value
+    readonly property Flickable dummy: Flickable {}
+
+
+    function getNewPosition(flickable, wheel) {
+        // wheel.pixelDelta will be available on high resolution trackpads.
+        // Otherwise use wheel.angleDelta, which is available from mouses and
+        // low resolution trackpads.
+        // When higher pixelDelta, more scroll will be applied
+        const pixelDelta =
+            wheel.pixelDelta.y ||
+            wheel.angleDelta.y / 8 * Qt.styleHints.wheelScrollLines
+
+        // Return current position if there was not any movement
+        if (flickable.contentHeight < flickable.height || !pixelDelta)
+            return flickable.contentY
+
+        const maxScroll =
+            flickable.contentHeight +
+            flickable.originY       +
+            flickable.bottomMargin  -
+            flickable.height
+        const minScroll = flickable.topMargin + flickable.originY
+
+        // Avoid overscrolling
+        return Math.max(
+            minScroll,
+            Math.min(maxScroll, flickable.contentY - pixelDelta)
+        )
+    }
+
+
+    Binding {
+        target: flickable
+        property: "maximumFlickVelocity"
+        value: mouseArea.enabled ? 0 : 4000.0
+    }
+
+    Binding {
+        target: flickable
+        property: "flickDeceleration"
+        value: mouseArea.enabled ? 0 : dummy.flickDeceleration
+    }
+}

src/gui/Base/HListView.qml

@@ -5,7 +5,6 @@ import QtQuick.Controls 2.12
 
 ListView {
     id: listView
-    interactive: allowDragging
     currentIndex: -1
     keyNavigationWraps: true
     highlightMoveDuration: theme.animationDuration
@@ -24,7 +23,7 @@ ListView {
     }
 
     ScrollBar.vertical: ScrollBar {
-        visible: listView.interactive || ! listView.allowDragging
+        visible: listView.interactive
     }
 
     // property bool debug: false
@@ -60,7 +59,6 @@ ListView {
     onSelectedCountChanged: if (! selectedCount) lastCheckedDelegateIndex = 0
 
 
-    property bool allowDragging: true
     property alias cursorShape: mouseArea.cursorShape
     property int currentItemHeight: currentItem ? currentItem.height : 0
 
@@ -120,22 +118,8 @@ ListView {
     }
 
 
-    Connections {
+    HKineticScrollingDisabler {
-        target: listView
-        enabled: ! listView.allowDragging
-        // interactive gets temporarily set to true below to allow wheel scroll
-        onDraggingChanged: listView.interactive = false
-    }
-
-    MouseArea {
         id: mouseArea
         anchors.fill: parent
-        enabled: ! parent.allowDragging || cursorShape !== Qt.ArrowCursor
-        acceptedButtons: Qt.NoButton
-        onWheel: {
-            // Allow wheel usage, will be back to false on any drag attempt
-            parent.interactive = true
-            wheel.accepted = false
-        }
     }
 }

src/gui/Utils.qml

@@ -325,7 +325,7 @@ QtObject {
     function flickPages(flickable, pages) {
         // Adapt velocity and deceleration for the number of pages to flick.
         // If this is a repeated flicking, flick faster than a single flick.
-        if (! flickable.interactive && flickable.allowDragging) return
+        if (! flickable.interactive) return
 
         const futureVelocity  = -flickable.height * pages
         const currentVelocity = -flickable.verticalVelocity
@@ -351,7 +351,7 @@ QtObject {
 
 
     function flickToTop(flickable) {
-        if (! flickable.interactive && flickable.allowDragging) return
+        if (! flickable.interactive) return
         if (flickable.visibleArea.yPosition < 0) return
 
         flickable.contentY -= flickable.contentHeight
@@ -361,7 +361,7 @@ QtObject {
 
 
     function flickToBottom(flickable) {
-        if (! flickable.interactive && flickable.allowDragging) return
+        if (! flickable.interactive) return
         if (flickable.visibleArea.yPosition < 0) return
 
         flickable.contentY = flickable.contentHeight - flickable.height