I'm using the following code, yes its incomplete and pretty little sphagetti as:
WidgetsBinding.instance!.handlePointerEvent(PointerDownEvent(pointer: 0, position: Offset(Get.width/2,Get.height/2)));
WidgetsBinding.instance!.handlePointerEvent(PointerMoveEvent(
pointer: 0,
//timeStamp: Duration(seconds:10),
position: Offset(Get.width/2+10,Get.height/2),
// delta: Offset(-10,Get.height/2),
// distanceMax: 0.05,
));
WidgetsBinding.instance!.handlePointerEvent(PointerUpEvent(pointer: 0),);
I'm trying to simulate a pointer drag on the screen, considering the screen is in landscape mode, from the middle of screen, to probably 10pixels+, to scroll the content a bit on a button-press. But the scroll is happening very fast, and sometimes scrolls with variable speed.
Could anyone recommend something?
Thanks to #pskink, the code he provided has been very helpful, and does answer the question too
late Animation<Offset> animation;
#override
void initState() {
super.initState();
final controller = AnimationController(vsync: this, duration: Duration(milliseconds: 300));
controller.addListener(_listener);
animation = Tween(begin: Offset(100, 100), end: Offset(200, 150)).animate(controller);
print('handle down event');
controller.forward().then((value) => print('handle up event'));
}
_listener() {
print('handle move event ${animation.value}');
}
Related
I made an automatic scrolling bar in flutter, the way I made it scroll automatically by using a combination of a timer and scroll controller, and then I linked the scroll controller to a regular ListView.builder, blew is the implementation of my way to do it
#override
void initState() {
super.initState();
int _length = widget.items.length;
currentItems = widget.items;
// scroll smothly to the end of the list then reverse the scroll
bool isAscending = true;
_timer = Timer.periodic(const Duration(milliseconds: 3000), (timer) {
if (isAscending) {
_currentIndex++;
if (_currentIndex == currentItems.length) {
isAscending = !isAscending;
}
}
if (!isAscending) {
_currentIndex--;
if (_currentIndex == 0) {
isAscending = !isAscending;
}
}
_scrollController.animateTo(_currentIndex * 304.0,
duration: const Duration(milliseconds: 3000), curve: Curves.linear);
});
}
my problem here is when I navigate to another screen or press the phone's home button and stay away from this widget for a while and then come back, I'd find it scrolling so fast to catch the currentIndex ( which is far away from where I left it ) in a period of time that I specified for the .animateTo method, I'm guessing the solution is to somehow pause the timer when I'm not in the same route, but I didn't find any reference of how to implement that
In flutter canvas if you try to draw two lines one above the other on the overlap the result line becomes larger. Below the code and an image with the result.
class MyPainter extends CustomPainter {
#override
void paint(Canvas canvas, Size size) {
canvas.drawLine(const Offset(100, 100), const Offset(200, 200), Paint());
canvas.drawLine(const Offset(100, 100), const Offset(400, 400), Paint());
}
#override
bool shouldRepaint(covariant CustomPainter oldDelegate) {
return false;
}
}
Line overlap
I hope it can be visible because the difference is very little.
In the project I'm working in, I don't want this to happen. Any suggestions?
Thank you very much
i have a screen that scans qr code and sends some informations to my db, when i navigate to camera page first time camera works perfectly but when i navigate to another page then back to camera page again camera is not working
if i save codes, camera works again. i think its about state but i cannot manage to solve this problem.
void initState() {
super.initState();
_animationController =
AnimationController(vsync: this, duration: const Duration(seconds: 1));
_animation = Tween<double>(begin: 0, end: 1).animate(CurvedAnimation(
parent: _animationController, curve: Curves.easeInOutCirc));
_animationController.forward();
}
void dispose() {
try {
qrViewController?.dispose();
} catch (e) {
print("error");
}
super.dispose();
}
Future<void> reassemble() async {
// TODO: implement reassemble
super.reassemble();
if (Platform.isAndroid) {
await qrViewController!.pauseCamera();
}
qrViewController!.resumeCamera();
}
void onQrViewCreated(QRViewController qrViewController) {
setState(() {
this.qrViewController = qrViewController;
});
qrViewController.scannedDataStream.listen((event) async {}
}
I changed my qr_code_scanner package with same publisher's mobile_scanner and this is working well
I have a requirement where I need to hide/show a widget ocassionally.
The widget is sitting right at the bottom of my layout. Immediately, the app loads I initially hide the widget by calling _slideAnimationController?.forward(); and then I noticed the widget is hidden but a white background was left behind by the SlideTransition widget, how can I remove this white background?
I don't want my users to know that there is a widget at the bottom until it is actually necessary to display it again using the SlideTransition.
Here is my code:
void initControllers() {
_scrollController.addListener(_scrollHandler);
_slideAnimationController =
AnimationController(vsync: this, duration: Duration(milliseconds: 100));
_slideAnimOffset = Tween<Offset>(begin: Offset.zero, end: Offset(0.0, 1.0))
.animate(_slideAnimationController!);
_slideAnimationController?.forward();
}
void _scrollHandler() {
if (_scrollController.position.atEdge) {
if (_scrollController.position.pixels != 0) {
_slideAnimationController?.reverse();
} else {
_slideAnimationController?.forward();
}
}
}
Here is my build method:
.....
SlideTransition(
position: _slideAnimOffset!,
child: Container(width:100,height:100), //When the animation runs and the container is hidden, a weird white background is left off. I don't want that white background at all. Once it is hidden, it should be fully transparent.
),
.....
And my initState is as below:
#override
initState() {
tintSystemChrome();
initControllers();
super.initState();
}
Any insights would be truly appreciated.
Thank you.
I have a similar problem to yours.
I ended up using the AnimatedAlign to achieve the slide in/out animation.
Here is the sample code:
AnimatedAlign(
duration: const Duration(milliseconds: 100),
alignment: Alignment.topCenter,
heightFactor: isVisible ? 1.0 : 0.0,
child: Container(width:100,height:100),
);
For my widget the animation I have is going down half way because I am using this:
TweenSequenceItem<Alignment>(
tween: AlignmentTween(
begin: Alignment.topCenter, end: Alignment.bottomCenter),
weight: 1.0),
I have determined when using topCenter to bottomCenter it seems to traverse down half way when the animation is running.
Result:
What I want it to do is to go down all the way on the screen, would I specify coordinates for that? If that is the way how would those coordinates beceome dynamic across different screen sizes?
Code:
class _BouncingBallState extends State<BouncingBall>
with TickerProviderStateMixin {
AnimationController controller;
Animation<Alignment> alignmentAnimation; // Create animation object
void initState() {
super.initState();
controller = AnimationController(
vsync: this,
duration: Duration(seconds: 60),
);
controller.repeat(); // Make animation repeat
// Initialize using TweenSequence, that contains TweenSequenceItem, we can add multiple TweenSequenceItem as per our animation requirement
alignmentAnimation = TweenSequence<Alignment>([
// First point move from top center to bottom center
TweenSequenceItem<Alignment>(
tween: AlignmentTween(
begin: Alignment.topCenter, end: Alignment.bottomCenter),
weight: 1.0),
}