In one of my mobile QML applications, I need to know when the handset orientation changes. The runtime knows but it doesn’t offer a signal to my code. Here is a QML hack that observes when orientation changes. It watches both height and width for changes. When they have both changed, it sets a boolean property to ‘true’. This works on handsets because both height and width change when orientation changes. It probably won’t work on a desktop because there it’s easy to change one without the other.
- /*
- Hack to observe changes in orientation from portrait to landscape in a Rectangle.
- Observation: On handsets, both the width and the height of the
- Rectangle will change when orientation changes. There is no way to
- catch both changes at the same time, so we catch them individually
- and set corresponding bools so we can remember the events. When we
- observe that both flags are 'true', we determine the orientation
- and set both bools back to 'false'.
- */
- property bool changeOfWidth: false
- property bool changeOfHeight: false
- property bool newOrientation: false
- onWidthChanged: {changeOfWidth = true; newOrientation = (changeOfWidth && changeOfHeight)}
- onHeightChanged: {changeOfHeight = true; newOrientation = (changeOfWidth && changeOfHeight)}
- onNewOrientationChanged: {
- if (newOrientation) {
- changeOfWidth = false;
- changeOfHeight = false;
- if (width > height) {
- // landscape
- console.log("landscape")
- } else {
- // portrait
- console.log("portrait")
- }
- }
- }
