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nextsummer33/iphone-uiview-inner-shadow.m

Created July 17, 2013 06:58
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  1. Ku4nCheang renamed this gist Jul 17, 2013. 1 changed file with 0 additions and 0 deletions.
    0 iphone-uiview-inner-shadow → iphone-uiview-inner-shadow.m
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    File renamed without changes.
  2. Ku4nCheang created this gist Jul 17, 2013.
    57 changes: 57 additions & 0 deletions iphone-uiview-inner-shadow
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,57 @@
    CGRect bounds = [self bounds];
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGFloat radius = 0.5f * CGRectGetHeight(bounds);


    // Create the "visible" path, which will be the shape that gets the inner shadow
    // In this case it's just a rounded rect, but could be as complex as your want
    CGMutablePathRef visiblePath = CGPathCreateMutable();
    CGRect innerRect = CGRectInset(bounds, radius, radius);
    CGPathMoveToPoint(visiblePath, NULL, innerRect.origin.x, bounds.origin.y);
    CGPathAddLineToPoint(visiblePath, NULL, innerRect.origin.x + innerRect.size.width, bounds.origin.y);
    CGPathAddArcToPoint(visiblePath, NULL, bounds.origin.x + bounds.size.width, bounds.origin.y, bounds.origin.x + bounds.size.width, innerRect.origin.y, radius);
    CGPathAddLineToPoint(visiblePath, NULL, bounds.origin.x + bounds.size.width, innerRect.origin.y + innerRect.size.height);
    CGPathAddArcToPoint(visiblePath, NULL, bounds.origin.x + bounds.size.width, bounds.origin.y + bounds.size.height, innerRect.origin.x + innerRect.size.width, bounds.origin.y + bounds.size.height, radius);
    CGPathAddLineToPoint(visiblePath, NULL, innerRect.origin.x, bounds.origin.y + bounds.size.height);
    CGPathAddArcToPoint(visiblePath, NULL, bounds.origin.x, bounds.origin.y + bounds.size.height, bounds.origin.x, innerRect.origin.y + innerRect.size.height, radius);
    CGPathAddLineToPoint(visiblePath, NULL, bounds.origin.x, innerRect.origin.y);
    CGPathAddArcToPoint(visiblePath, NULL, bounds.origin.x, bounds.origin.y, innerRect.origin.x, bounds.origin.y, radius);
    CGPathCloseSubpath(visiblePath);

    // Fill this path
    UIColor *aColor = [UIColor redColor];
    [aColor setFill];
    CGContextAddPath(context, visiblePath);
    CGContextFillPath(context);


    // Now create a larger rectangle, which we're going to subtract the visible path from
    // and apply a shadow
    CGMutablePathRef path = CGPathCreateMutable();
    //(when drawing the shadow for a path whichs bounding box is not known pass "CGPathGetPathBoundingBox(visiblePath)" instead of "bounds" in the following line:)
    //-42 cuould just be any offset > 0
    CGPathAddRect(path, NULL, CGRectInset(bounds, -42, -42));

    // Add the visible path (so that it gets subtracted for the shadow)
    CGPathAddPath(path, NULL, visiblePath);
    CGPathCloseSubpath(path);

    // Add the visible paths as the clipping path to the context
    CGContextAddPath(context, visiblePath);
    CGContextClip(context);


    // Now setup the shadow properties on the context
    aColor = [UIColor colorWithRed:0.0f green:0.0f blue:0.0f alpha:0.5f];
    CGContextSaveGState(context);
    CGContextSetShadowWithColor(context, CGSizeMake(0.0f, 1.0f), 3.0f, [aColor CGColor]);

    // Now fill the rectangle, so the shadow gets drawn
    [aColor setFill];
    CGContextSaveGState(context);
    CGContextAddPath(context, path);
    CGContextEOFillPath(context);

    // Release the paths
    CGPathRelease(path);
    CGPathRelease(visiblePath);