Details
-
Bug
-
Resolution: Unresolved
-
P2: Important
-
None
-
6.5.4, 6.6.2, 6.7.0 Beta3
Description
Code
import QtQuick import QtQuick.Controls.Basic Window { id: window width: 800 height: 600 visible: true Overlay.overlay.width: window.width * 3/4 Overlay.overlay.height: window.height * 3/4 Overlay.overlay.anchors.centerIn: window.contentItem /* // WORKAROUND: Replace the bindings above with the following Overlay.overlay.anchors.fill: board Item { id: board width: window.width * 3/4 height: window.height * 3/4 anchors.centerIn: parent } */ Popup { id: popup width: window.width / 2 height: window.height / 2 anchors.centerIn: parent dim: true opacity: 0.5 } Text { anchors.centerIn: parent text: `Window: ${window.width}x${window.height}` + '\n' + `Overlay: (${window.Overlay.overlay.x}, ${window.Overlay.overlay.y}) ${window.Overlay.overlay.width}x${window.Overlay.overlay.height}` } Row { spacing: 10 Button { text: "Pop Up" onClicked: popup.open() } Button { text: "Kick Width" onClicked: { window.width += 1 window.width -= 1 } } Button { text: "Kick Height" onClicked: { window.height += 1 window.height -= 1 } } } }
Steps to reproduce
- Run the example code above
- Click "Pop Up"
- Click "Kick Width" and then click "Pop Up"
- Click "Kick Height" and then click "Pop Up"
- Click "Pop Up" and then resize the window freely
Expected outcomes
- The Popup's dimmer is always 3/4 the size of the window
- Also, Steps #2-#4: The text reports "Overlay: (100, 75) 650x450" throughout
Actual outcomes
- Step #2: "Overlay: (0, 0) 800x600"
- Step #3: "Overlay: (100, 0) 600x600"
- Step #4: "Overlay: (0, 75) 800x450"
- Step #5: The dimmer fluctuates between being too wide, or too tall, or just right (at 3/4 the size of the window)
Workaround
Instead of binding width/height, create an invisible Item with the geometry that you want the dimmer to be. Then, use anchors.fill to make the Overlay's geometry match that Item (see code above)
Analysis
This issue occurs because QQuickOverlay::updateGeometry() calls setSize() and setPosition().
The workaround works because, in the current implementation of Qt Quick, anchors are calculated after size and position are applied so the results of QQuickOverlay::updateGeometry() are overwritten. But I don't know if this behaviour is guaranteed to persist into the future.
It would be good if QQuickOverlay could be bound to the geometry of the QQuickWindow::contentItem() at initialization, but then allow the user to override that binding from QML.
Use cases
- Our Boot2Qt documentation shows how to switch between portrait and lanscape views. But if the GUI contains Popups/ComboBoxes/Drawers/Menus then we also need to manually change the Overlay's geometry to apply this trick.
- If we spin the Popup (say, for an animated effect), we need to enlarge the dimmer so that it covers whole window throughout the animation:
import QtQuick import QtQuick.Controls.Basic Window { id: window width: 800 height: 600 visible: true property double diagonal: Math.sqrt(window.width*window.width + window.height*window.height) Popup { id: popup width: window.width / 2 height: window.height / 2 anchors.centerIn: parent dim: true PropertyAnimation { id: anim target: popup.Overlay.overlay property: "rotation" from: 0 to: 360 duration: 1000 } Overlay.modeless: Rectangle { color: "blue" opacity: 0.5 width: window.diagonal // DOESN'T WORK height: window.diagonal // DOESN'T WORK } Button { anchors.centerIn: parent text: "Spin!" onClicked: anim.start() } } Button { text: "Pop Up" onClicked: popup.open() } /* // WORKAROUND Overlay.overlay.anchors.fill: board Item { id: board width: window.diagonal height: window.diagonal anchors.centerIn: parent } */ }
Attachments
Issue Links
- relates to
-
QTBUG-118460 Overlay.rotation gets discarded when window is resized
- Closed
-
QTBUG-124744 [Reg 6.7.0 -> dev] Bindings on width/height of ApplicationWindow.background are not respected
- Closed
-
QTBUG-95874 QtQuick ApplicationWindow and Overlay.overlay conceptual problems
- Reported
- replaces
-
QTBUG-122771 Resizing the Window overrides bindings on Overlay.overlay
- Closed
Gerrit Reviews
For Gerrit Dashboard: QTBUG-122962 | ||||||
---|---|---|---|---|---|---|
# | Subject | Branch | Project | Status | CR | V |
554384,1 | WIP: Overlay: Respect existing bindings to geometry | dev | qt/qtdeclarative | Status: NEW | -2 | +1 |