Implement shift+click/A-B message selection

TODO.md

@@ -2,7 +2,6 @@
 
 - Long-press-drag to select multiple messages on touch
 - Drag to select multiple messages on non-touch
-- Shift+click to select everything in between
 
 - Drag-scrolling in room pane a tiny bit activates the delegates
 

src/gui/Base/HListView.qml

@@ -64,22 +64,35 @@ ListView {
         }
     }
 
+    onSelectedCountChanged: if (! selectedCount) lastCheckedDelegateIndex = 0
+
 
     property bool allowDragging: true
     property alias cursorShape: mouseArea.cursorShape
     property int currentItemHeight: currentItem ? currentItem.height : 0
+
     property var checkedDelegates: ({})
+    property int lastCheckedDelegateIndex: 0
     property int selectedCount: Object.keys(checkedDelegates).length
 
 
     function delegatesChecked(...indices) {
+        print( indices)
         for (const i of indices) {
             const model = listView.model.get(i)
             checkedDelegates[model.id] = model
         }
+
+        lastCheckedDelegateIndex = indices.slice(-1)[0]
+
         checkedDelegatesChanged()
     }
 
+    function delegatesFromLastToHereChecked(here) {
+        const indices = utils.range(lastCheckedDelegateIndex, here)
+        eventList.delegatesChecked(...indices)
+    }
+
     function delegatesUnchecked(...indices) {
         for (const i of indices) {
             const model = listView.model.get(i)

src/gui/Pages/Chat/Timeline/EventContent.qml

@@ -183,6 +183,7 @@ HRowLayout {
             PointHandler {
                 id: mousePointHandler
                 acceptedButtons: Qt.LeftButton
+                acceptedModifiers: Qt.NoModifier
                 acceptedPointerTypes:
                     PointerDevice.GenericPointer | PointerDevice.Eraser
 
@@ -206,6 +207,24 @@ HRowLayout {
                 property bool checkedNow: false
             }
 
+            PointHandler {
+                id: mouseShiftPointHandler
+                acceptedButtons: Qt.LeftButton
+                acceptedModifiers: Qt.ShiftModifier
+                acceptedPointerTypes:
+                    PointerDevice.GenericPointer | PointerDevice.Eraser
+
+                onActiveChanged: {
+                    if (active &&
+                            ! eventDelegate.checked &&
+                            (! parent.hoveredLink ||
+                            ! parent.enableLinkActivation)) {
+
+                        eventList.delegatesFromLastToHereChecked(model.index)
+                    }
+                }
+            }
+
             TapHandler {
                 id: touchTapHandler
                 acceptedButtons: Qt.LeftButton
@@ -234,7 +253,8 @@ HRowLayout {
                 z: -100
                 color: eventDelegate.checked &&
                        ! contentLabel.selectedText &&
-                       ! mousePointHandler.active ?
+                       ! mousePointHandler.active &&
+                       ! mouseShiftPointHandler.active ?
                        theme.chat.message.checkedBackground :
 
                        isOwn?

src/gui/Pages/Chat/Timeline/EventDelegate.qml

@@ -57,8 +57,6 @@ HColumnLayout {
             combine   ? theme.spacing / (compact ? 4 : 2) :
             theme.spacing * (compact ? 1 : 2)
 
-    readonly property alias leftTapHandler: leftTapHandler
-
     // Needed because of eventList's MouseArea which steals the
     // HSelectableLabel's MouseArea hover events
     onCursorShapeChanged: eventList.cursorShape = cursorShape
@@ -114,11 +112,17 @@ HColumnLayout {
     }
 
     TapHandler {
-        id: leftTapHandler
         acceptedButtons: Qt.LeftButton
+        acceptedModifiers: Qt.NoModifier
         onTapped: toggleChecked()
     }
 
+    TapHandler {
+        acceptedButtons: Qt.LeftButton
+        acceptedModifiers: Qt.ShiftModifier
+        onTapped: eventList.delegatesFromLastToHereChecked(model.index)
+    }
+
     TapHandler {
         acceptedButtons: Qt.RightButton
         acceptedPointerTypes: PointerDevice.GenericPointer | PointerDevice.Pen
@@ -151,6 +155,13 @@ HColumnLayout {
             onTriggered: eventList.checkedDelegates = {}
         }
 
+        HMenuItem {
+            visible: model.index !== 0
+            icon.name: "select-until-here"
+            text: qsTr("Select until here")
+            onTriggered: eventList.delegatesFromLastToHereChecked(model.index)
+        }
+
         HMenuItem {
             id: copyMedia
             icon.name: "copy-link"

src/gui/Pages/Chat/Timeline/EventImage.qml

@@ -83,6 +83,7 @@ HMxcImage {
 
 
     TapHandler {
+        acceptedModifiers: Qt.NoModifier
         onTapped:
             eventList.selectedCount ?
             eventDelegate.toggleChecked() : getOpenUrl(Qt.openUrlExternally)
@@ -90,6 +91,14 @@ HMxcImage {
         gesturePolicy: TapHandler.ReleaseWithinBounds
     }
 
+    TapHandler {
+        acceptedModifiers: Qt.ShiftModifier
+        onTapped:
+            eventList.delegatesFromLastToHereChecked(singleMediaInfo.index)
+
+        gesturePolicy: TapHandler.ReleaseWithinBounds
+    }
+
     HoverHandler {
         id: hover
         onHoveredChanged: {

src/gui/Utils.qml

@@ -83,6 +83,26 @@ QtObject {
     }
 
 
+    function range(startOrEnd, end=null, ) {
+        // range(3) → [0, 1, 2, 3]
+        // range(3, 6) → [3, 4, 5, 6]
+        // range(3, -1) → [3, 2, 1, 0, -1]
+
+        const numbers = []
+        let realStart = end ? startOrEnd : 0
+        let realEnd   = end ? end : startOrEnd
+
+        if (realEnd < realStart)
+            for (let i = realStart;  i >= realEnd; i--)
+                numbers.push(i)
+        else
+            for (let i = realStart;  i <= realEnd; i++)
+                numbers.push(i)
+
+        return numbers
+    }
+
+
     function isEmptyObject(obj) {
         return Object.entries(obj).length === 0 && obj.constructor === Object
     }

src/icons/thin/select-until-here.svg

@@ -0,0 +1,3 @@
+<svg height="24" viewBox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg">
+    <path d="m11 24v-2h-4v2zm8-22h3v3h2v-5h-5zm-19 15h2v-4h-2zm0-6h2v-4h-2zm2-6v-3h3v-2h-5v5zm22 2h-2v4h2zm0 6h-2v4h2zm-2 6v3h-3v2h5v-5zm-17 3h-3v-3h-2v5h5zm12 2v-2h-4v2zm-6-22v-2h-4v2zm6 0v-2h-4v2zm0 11h-4v4h-2v-4h-4v-2h4v-4h2v4h4z"/>
+</svg>