CODEWITHSUNDEEP
iosobjective-c
Rajesh
Rajesh

Reputation: 622

Undo and Redo functionality in drawing application ios

I am working on a drawing app and I am able to draw with my finger touch. Now I am trying to implement clear, undo, and redo functionality.

In my view controller I have two IBAction methods for "clearAll" and "Undo". I have created a custom class called drawing.h and .m where I have written functions for handling touch events. Below are my functions.

The problem is undo and redo work but the last color select in all line in drawn in undo and redo.

drowing in line view

after undo screensort

Upvotes: 0

Views: 784

Answers (1)

Rajesh
Rajesh

Reputation: 622

I Have Mistake In Touch End Method In Array Last Array Not Remove on last object 

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
   UIGraphicsBeginImageContext(self.tempimage.bounds.size);
        [self.tempimage.layer renderInContext:UIGraphicsGetCurrentContext()];
  rawImage = UIGraphicsGetImageFromCurrentImageContext();
   [self.tempimage.image drawInRect:CGRectMake(0, 0, tempimage.frame.size.width, tempimage.frame.size.height) blendMode:blendmode alpha:opacity];
    UIGraphicsEndImageContext();
#if PUSHTOFILE
   lineIndex++;
    [self performSelectorInBackground:@selector(writeFilesBG)
                           withObject:nil];
#else
    NSDictionary *lineInfo = [NSDictionary dictionaryWithObjectsAndKeys:rawImage, @"IMAGE",nil];
    [pointsArray addObject:lineInfo];
    UIBezierPath *_path=[pointsArray lastObject];
    [_stack addObject:_path];
    [pointsArray removeLastObject];
    [self.tempimage setNeedsDisplay];
#endif
}

Upvotes: 1

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