before I set the painter as finished I would like to:

• know if anything has been painted at all (true/false)
• get a snapshot image of the drawing but still let the user draw more is that possible?

Hey, Do you guys plan to upgrade to support Dart Null Safety?

 dart pub outdated --mode=null-safety

Resolving...
Showing dependencies that are currently not opted in to null-safety.
[✗] indicates versions without null safety support.
[✓] indicates versions opting in to null safety.   

Computing null safety support...
Package Name                          Current        Upgradable      Resolvable  Latest

direct dependencies:
...
painter                               ✗0.4.0         ✗0.4.0          -           ✗0.4.0
...

Example usage:

controller.decorationForPainter = new BoxDecoration(
      image: new DecorationImage(
        image: ExactAssetImage('assets/bg.jpg'),
      ),
    );

I am not sure if this is the best approach, as I am still quite new to flutter. Equally this does not satisfy the issue request (#3 ) of using an image from the gallery.

I have this error when download the project A value of type 'Future' can't be assigned to a variable of type 'Image'. in the method of class painter.

In the line 166 to 168:

Image toImage(){ return picture.toImage(width, height); // here! }

I would like to save the drawing as a list of lists. More specifically, a list of paths that each has a list of offset points in (x and y). Is this possible using the PainterController in this package?

Hi When we try to convert the painter to image/png it throws error saying "operation failed" works in most of devices but facing issue in some iOS and some android devices[ tested in samsung s10 and honor devices]

any workaround or solution to get it fixed.

my logic is simple, pasting here....

try{
  var imgToSendBack =await _controller.finish().toPNG();
}catch(e){
print('save image catch error ${e.toString()}');
}

Add a background image to canvas via controller

Example updated with FAB to set background image (if Background image set the background colour is not taken into account.)

I hope this helps setting background image

It would be cool have an option to enable the thickness of the pencil based on the speed of the cursor. I tried to draw something in native iOS and it seems to behave like that! What do you think?

Here is PR with code change that allows user to set erase mode. Set controller.eraseMode = true for erase mode.

Note: This works only for transparent background. If You want this to work with colored background, further code changes are needed. My suggestion is moving background to another canvas, by simply using Stack and inserting simple box view below painter layer.

When i run the app on Web (Chrome) works like a charm (i make a signature, goes to the next step and at the end i made a base64 String with the data of the PNG (.toPNG()), but when i change to mobile the image don't render correctly (only do like 24 pixels of height) it does all the width (like 323 pixels).

Container with a button to generate the PNG and storage in a variable.

Button to print the base64 string

And this is the only result when i run the app in a mobile device (It's missing a lot of lines)

How it looks (the image have the correct dimensions but the content is missing):

Guys, is there any way we can add our custom drawing shape to cavas ??

Or any way we can get instance of canvas which can help to get painted over it ? Just like any circle on canvas as shown in image.

Right now, we don't have any callback to check from where the user is started drawing on the screen. We are not getting any coordinates on the screen. Need help with this!

Hi amazing developer,

This library does not have flutter_lints applied, so I added it as a dependency. Also, the warning that was generated when adding flutter_lints to the dependency has been optimized here so that it does not affect the existing behavior. Please check this PR and merge it if there is no problem.

Thank you.

I noticed a crash when attempting to erase in my Flutter web application only on mobile web browsers. I then tested it with the example code from pub.dev and experienced the same behavior.

It appears that paint.blendMode = BlendMode.clear; is the culprit.

One quick workaround I found is to just simulate an erase stroke by painting using the backgroundColor.

if (_eraseMode) {
  paint.blendMode = BlendMode.srcOver;
  paint.color = backgroundColor;
}

However, in my app, my PainterController has backgroundColor = Colors.transparent.

I am not that familiar with different blend modes and if there is another way to achieve my desired result.