[ui] Added selectionLine and delegate variant to allow drawing an edge

The drawn edge is checked for intersection with individual node edges and any edge found interesecting is emitted when the selection ends

meshroom/ui/qml/Controls/DelegateSelectionLine.qml

@@ -0,0 +1,31 @@
+import QtQuick
+import Meshroom.Helpers
+
+/*
+A SelectionLine that can be used to select delegates in a model instantiator (Repeater, ListView...).
+Interesection test is done in the coordinate system of the container Item, using delegate's bounding boxes.
+The list of selected indices is emitted when the selection ends.
+*/
+
+SelectionLine {
+    id: root
+
+    // The Item instantiating the delegates.
+    property Item modelInstantiator
+    // The Item containing the delegates (used for coordinate mapping).
+    property Item container
+    // Emitted when the selection has ended, with the list of selected indices and modifiers.
+    signal delegateSelectionEnded(list<int> indices, int modifiers)
+
+    onSelectionEnded: function(selectionRect, modifiers) {
+        let selectedIndices = [];
+        const mappedSelectionRect = mapToItem(container, selectionRect);
+        for (var i = 0; i < modelInstantiator.count; ++i) {
+            const delegate = modelInstantiator.itemAt(i);
+            if (delegate.intersects(mappedSelectionRect)) {
+                selectedIndices.push(i);
+            }
+        }
+        delegateSelectionEnded(selectedIndices, modifiers);
+    }
+}

meshroom/ui/qml/Controls/SelectionLine.qml

@@ -0,0 +1,77 @@
+import QtQuick
+import QtQuick.Shapes
+
+/*
+Simple selection line that can be used by a MouseArea.
+
+Usage:
+1. Create a MouseArea and a selectionShape.
+2. Bind the selectionShape to the MouseArea by setting the `mouseArea` property.
+3. Call startSelection() with coordinates when the selection starts.
+4. Call endSelection() when the selection ends.
+5. Listen to the selectionEnded signal to get the rectangle whose Diagonal is the selection line.
+*/
+
+Item {
+    id: root
+
+    property MouseArea mouseArea
+
+    readonly property bool active: mouseArea.drag.target == dragTarget
+
+    signal selectionEnded(rect selectionRect, int modifiers)
+
+    function startSelection(mouse) {
+        dragTarget.startPos.x = dragTarget.x = mouse.x;
+        dragTarget.startPos.y = dragTarget.y = mouse.y;
+        dragTarget.modifiers = mouse.modifiers;
+        mouseArea.drag.target = dragTarget;
+    }
+
+    function endSelection() {
+        if (!active) {
+            return;
+        }
+        mouseArea.drag.target = null;
+        const rect = Qt.rect(selectionShape.x, selectionShape.y, selectionShape.width, selectionShape.height)
+        selectionEnded(rect, dragTarget.modifiers);
+    }
+
+    visible: active
+
+    Item {
+        id: selectionShape
+        x: dragTarget.startPos.x
+        y: dragTarget.startPos.y
+        width: dragTarget.x - dragTarget.startPos.x
+        height: dragTarget.y - dragTarget.startPos.y
+
+        Shape {
+            id: dynamicLine;
+            width: selectionShape.width;
+            height: selectionShape.height;
+            anchors.fill: parent;
+
+            ShapePath {
+                strokeWidth: 2;
+                strokeStyle: ShapePath.DashLine;
+                strokeColor: "#FF0000";
+                dashPattern: [3, 2];
+
+                startX: 0;
+                startY: 0;
+
+                PathLine {
+                    x: selectionShape.width;
+                    y: selectionShape.height;
+                }
+            }
+        }
+    }
+
+    Item {
+        id: dragTarget
+        property point startPos
+        property var modifiers
+    }
+}

meshroom/ui/qml/Controls/qmldir

@@ -18,4 +18,6 @@ MScrollBar 1.0 MScrollBar.qml
 MSplitView 1.0 MSplitView.qml
 DirectionalLightPane 1.0 DirectionalLightPane.qml
 SelectionBox 1.0 SelectionBox.qml
-DelegateSelectionBox 1.0 DelegateSelectionBox.qml
+SelectionLine 1.0 SelectionLine.qml
+DelegateSelectionBox 1.0 DelegateSelectionBox.qml
+DelegateSelectionLine 1.0 DelegateSelectionLine.qml