QmlDesigner: Fix PopupDialog popup location

* Restrict popup location to single screen given by global position
* Reintroduce PopupDialog title bar drag
* Fix global popup show on linux

Change-Id: If1923151cb9d0ec4286f27aeae2baa292e017eb5
Reviewed-by: Qt CI Patch Build Bot <ci_patchbuild_bot@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

share/qtcreator/qmldesigner/connectionseditor/ConnectionsDialog.qml

@@ -49,7 +49,7 @@ StudioControls.PopupDialog {
                 root.close()
             }
             function onPopupShouldOpen() {
-                root.showGlobal()
+                Qt.callLater(root.showGlobal)
             }
         }
     }

share/qtcreator/qmldesigner/propertyEditorQmlSources/imports/StudioControls/PopupDialog.qml

@@ -33,9 +33,8 @@ QtObject {
 
     signal closing(close: var)
 
-    function showGlobal()
-    {
-        var pos =  WindowManager.globalCursorPosition();
+    function showGlobal() {
+        var pos = WindowManager.globalCursorPosition()
         root.__itemGlobal = Qt.rect(pos.x, pos.y, 300, 20)
         root.chevronVisible = false
         root.layout()
@@ -57,11 +56,8 @@ QtObject {
     }
 
     function layout() {
-        // Setup
-        var screen = Qt.rect(0, //Screen.virtualX, // TODO
-                             0, //Screen.virtualY, // TODO
-                             Screen.desktopAvailableWidth,
-                             Screen.desktopAvailableHeight)
+        let position = Qt.point(root.__itemGlobal.x, root.__itemGlobal.y)
+        var screen = WindowManager.getScreenGeometry(position)
 
         // Collect region information
         let edges = window.getRegions(screen, root.__itemGlobal)
@@ -165,9 +161,18 @@ QtObject {
             var targetCenter = Qt.point(target.x + (target.width * 0.5),
                                         target.y + (target.height * 0.5))
 
+            // Just as a reminder why calculating custom right and bottom:
+            // > Note that for historical reasons this function returns top() + height() - 1;
+            // > use y() + height() to retrieve the true y-coordinate.
+            let sourceRight = source.x + source.width
+            let sourceBottom = source.y + source.height
+
             // TOP
             let topAnchor = Qt.point(targetCenter.x, target.y)
-            let topRegion = Qt.rect(source.x, source.y, source.width, Math.max(0, topAnchor.y))
+            let topRegion = Qt.rect(source.x,
+                                    source.y,
+                                    source.width,
+                                    (topAnchor.y < source.top) ? 0 : Math.abs(topAnchor.y - source.top))
 
             edges[Qt.TopEdge] = {
                 anchor: topAnchor,
@@ -180,7 +185,7 @@ QtObject {
             let rightAnchor = Qt.point(target.x + target.width, targetCenter.y)
             let rightRegion = Qt.rect(rightAnchor.x,
                                       source.y,
-                                      Math.max(0, source.width - rightAnchor.x),
+                                      (rightAnchor.x > sourceRight) ? 0 : Math.abs(sourceRight - rightAnchor.x),
                                       source.height)
 
             edges[Qt.RightEdge] = {
@@ -195,7 +200,7 @@ QtObject {
             let bottomRegion = Qt.rect(source.x,
                                        bottomAnchor.y,
                                        source.width,
-                                       Math.max(0, source.height - bottomAnchor.y))
+                                       (bottomAnchor.y > sourceBottom) ? 0 : Math.abs(sourceBottom - bottomAnchor.y))
 
             edges[Qt.BottomEdge] = {
                 anchor: bottomAnchor,
@@ -206,7 +211,10 @@ QtObject {
 
             // LEFT
             let leftAnchor = Qt.point(target.x, targetCenter.y)
-            let leftRegion = Qt.rect(source.x, source.y, Math.max(0, leftAnchor.x), source.height)
+            let leftRegion = Qt.rect(source.x,
+                                     source.y,
+                                     (leftAnchor.x < source.left) ? 0 : Math.abs(leftAnchor.x - source.left),
+                                     source.height)
 
             edges[Qt.LeftEdge] = {
                 anchor: leftAnchor,
@@ -392,6 +400,19 @@ QtObject {
                 width: parent.width
                 height: StudioTheme.Values.titleBarHeight
 
+                DragHandler {
+                    id: dragHandler
+
+                    target: null
+                    grabPermissions: PointerHandler.CanTakeOverFromAnything
+                    onActiveChanged: {
+                        if (dragHandler.active)
+                            window.startSystemMove() // QTBUG-102488
+
+                        root.chevronVisible = false
+                    }
+                }
+
                 Row {
                     id: row
                     anchors.fill: parent

src/plugins/qmldesignerbase/utils/windowmanager.cpp

@@ -8,6 +8,7 @@
 #include <QCursor>
 #include <QGuiApplication>
 #include <QMainWindow>
+#include <QScreen>
 #include <QWindow>
 
 namespace QmlDesignerBase {
@@ -43,4 +44,14 @@ QPoint WindowManager::globalCursorPosition()
     return QCursor::pos();
 }
 
+QRect WindowManager::getScreenGeometry(QPoint point)
+{
+    QScreen *screen = QGuiApplication::screenAt(point);
+
+    if (!screen)
+        return {};
+
+    return screen->geometry();
+}
+
 } // namespace QmlDesignerBase

src/plugins/qmldesignerbase/utils/windowmanager.h

@@ -25,6 +25,7 @@ public:
     static void registerDeclarativeType();
 
     Q_INVOKABLE QPoint globalCursorPosition();
+    Q_INVOKABLE QRect getScreenGeometry(QPoint point);
 
 signals:
     void focusWindowChanged(QWindow *window);