How to realize rotation gesture in Android

This article introduces the relevant knowledge of "how to achieve rotation gestures in Android". In the operation of practical cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Rotation gesture

Rotation gestures correspond to TransformGestureEvent. GESTURE_ROTATE event type. Like the zoom gesture, this event requires two fingers to touch the screen, but the two fingers slide in the opposite direction, such as twisting the switch clockwise or counterclockwise. Dealing with rotation gestures is the same as dealing with zoom gestures. You can modify the program GestureZoom slightly to change the event type GESTURE_ZOOM to GESTURE_ROTATE.

Loader.addEventListener (TransformGestureEvent.GESTURE_ROTATE, onRotate)

At the same time, write a new event response function onRotate, the code is as follows:

Private function onRotate (e:TransformGestureEvent): void {var p:Point = new Point (e.localX, e.localY); var parent_p:Point = this.globalToLocal (loader.localToGlobal (p)); / / plus the new rotation angle loader.rotation + = e.rotation; var parent_p2:Point = this.globalToLocal (loader.localToGlobal (p)); loader.x + = (parent_p.x-parent_p2.x) Loader.y + = (parent_p.y-parent_p2.y);}

Compared with the onZoom function in the previous section, the reader will find that there is only the following difference:

Loader.rotation + = e.rotation; this is the end of how to implement rotation gestures in Android. Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!