Revert "Revert "Implement selection across multiple MessageDelegates""

This reverts commit 3697146f44.

src/qml/RichLabel.qml

@@ -43,13 +43,18 @@ TextEdit {
      */
     property bool spoilerRevealed: !hasSpoiler.test(textMessage)
 
+    property bool isDelegate: false
+
     ListView.onReused: Qt.binding(() => !hasSpoiler.test(textMessage))
 
     persistentSelection: true
 
     // Work around QTBUG 93281
-    Component.onCompleted: if (text.includes("<img")) {
-        Controller.forceRefreshTextDocument(root.textDocument, root)
+    Component.onCompleted: {
+        updateSelection()
+        if (text.includes("<img")) {
+            Controller.forceRefreshTextDocument(root.textDocument, root)
+        }
     }
 
     text: "<style>
@@ -116,4 +121,26 @@ a{
         enabled: !parent.hoveredLink && !spoilerRevealed
         onTapped: spoilerRevealed = true
     }
+
+    Connections {
+        target: selectionArea
+        enabled: root.isDelegate
+        function onSelectionChanged() {
+            updateSelection();
+        }
+    }
+
+    function updateSelection() {
+        if (index < selectionArea.lowerIndex || index > selectionArea.upperIndex) {
+            root.select(0, 0);
+        } else if (index > selectionArea.lowerIndex && index < selectionArea.upperIndex) {
+            root.selectAll();
+        } else if (index === selectionArea.selectionStartIndex && index === selectionArea.selectionEndIndex) {
+            root.select(selectionArea.upperPos, selectionArea.lowerPos);
+        } else if (index === selectionArea.upperIndex) {
+            root.select(selectionArea.upperPos, root.length);
+        } else if (index === selectionArea.lowerIndex) {
+            root.select(0, selectionArea.lowerPos);
+        }
+    }
 }

src/qml/TextDelegate.qml

@@ -17,6 +17,14 @@ import org.kde.neochat.config
 MessageDelegate {
     id: root
 
+    function positionAt(x, y) {
+        let point = label.mapFromItem(root, x, y)
+        return label.positionAt(point.x, point.y)
+    }
+
+    property alias selectedText: label.selectedText
+
+
     /**
      * @brief The link preview properties.
      *
@@ -54,6 +62,7 @@ MessageDelegate {
                 acceptedButtons: Qt.LeftButton
                 onLongPressed: root.openContextMenu()
             }
+            isDelegate: true
         }
         Loader {
             Layout.fillWidth: true

src/qml/TimelineView.qml

@@ -341,6 +341,66 @@ QQC2.ScrollView {
             }
         }
 
+        function indexAtRelative(x, y) {
+            return indexAt(x + contentX, y + contentY)
+        }
+
+        MouseArea {
+            id: selectionArea
+
+            anchors.fill: parent
+
+            property int selectionStartIndex
+            property int selectionEndIndex
+            property int selectionStartPos
+            property int selectionEndPos
+
+            property int upperIndex: selectionStartIndex > selectionEndIndex ? selectionStartIndex : selectionEndIndex
+            property int upperPos: selectionStartIndex > selectionEndIndex ? selectionStartPos : (selectionStartIndex == selectionEndIndex ? (selectionStartPos > selectionEndPos ? selectionEndPos : selectionStartPos) : selectionEndPos)
+            property int lowerIndex: selectionStartIndex > selectionEndIndex ? selectionEndIndex : selectionStartIndex
+            property int lowerPos: selectionStartIndex > selectionEndIndex ? selectionEndPos : (selectionStartIndex == selectionEndIndex ? (selectionStartPos > selectionEndPos ? selectionStartPos : selectionEndPos) : selectionStartPos)
+
+            signal selectionChanged
+
+            function indexAndPos(x, y) {
+                const index = messageListView.indexAtRelative(x, y);
+                if (index == -1) {
+                    return;
+                }
+                const item = messageListView.itemAtIndex(index);
+                const relItemY = item.y - messageListView.contentY;
+                const pos = item.positionAt(x, y - relItemY);
+                return [index, pos]
+            }
+
+            onPressed: {
+                [selectionArea.selectionEndIndex, selectionArea.selectionEndPos] = selectionArea.indexAndPos(mouse.x, mouse.y);
+                [selectionArea.selectionStartIndex, selectionArea.selectionStartPos] = selectionArea.indexAndPos(mouse.x, mouse.y);
+                selectionChanged();
+            }
+            onPositionChanged: {
+                if (!pressed) {
+                    return
+                }
+                [selectionEndIndex, selectionEndPos] = selectionArea.indexAndPos(mouse.x, mouse.y);
+                selectionChanged();
+            }
+        }
+
+        Kirigami.Action {
+            onTriggered: {
+                var text = ""
+                for (let i = selectionArea.upperIndex; i >= selectionArea.lowerIndex; i--) {
+                    text += messageListView.itemAtIndex(i).selectedText
+                    if (i > selectionArea.lowerIndex) {
+                        text += " "
+                    }
+                }
+                Clipboard.saveText(text)
+            }
+            shortcut: "Ctrl+C"
+        }
+
         function showMaximizedMedia(index) {
             var popup = maximizeComponent.createObject(QQC2.ApplicationWindow.overlay, {
                     initialIndex: index