Multiple backgrounds!
body {
background: #eb01a5;
background-image: url("IMAGE_URL"); /* fallback */
background-image: url("IMAGE_URL"), linear-gradient(#eb01a5, #d13531); /* W3C */
}
These 2 lines are the fallback for any browser that doesn't do gradients.
See notes for stacking images only IE < 9 below.
- Line 1 sets a flat background color.
- Line 2 sets the background image fallback.
The final line sets a background image and gradient for browsers that can handle them.
- Line 3 is for all relatively modern browsers.
Nearly all current browsers have support for multiple background images and css backgrounds. See http://caniuse.com/#feat=css-gradients for browser support. For a good post on why you don't need multiple browser prefixes, see http://codepen.io/thebabydino/full/pjxVWp/
Layer Stack
It should be noted that the first defined image will be topmost in the stack. In this case, the image is on TOP of the gradient.
For more information about background layering see http://www.w3.org/TR/css3-background/#layering.
Stacking images ONLY (no gradients in the declaration) For IE < 9
IE9 and up can stack images this same way. You could use this to create a gradient image for ie9, though personally, I wouldn't. However to be noted when using only images, ie < 9 will ignore the fallback statement and not show any image. This does not happen when a gradient is included. To use a single fallback image in this case I suggest using Paul Irish's wonderful Conditional HTML element along with your fallback code:
.lte9 #target{ background-image: url("IMAGE_URL"); }
Background position, sizing etc.
Other properties that would apply to a single image may also be comma separated. If only 1 value is supplied, that will be applied to all stacked images including the gradient. background-size: 40px; will constrain both the image and the gradient to 40px height and width. However using background-size: 40px, cover; will make the image 40px and the gradient will cover the element. To only apply a setting to one image, set the default for the other: background-position: 50%, 0 0; or for browsers that support it use initial: background-position: 50%, initial;
You may also use the background shorthand, however this removes the fallback color and image.
body{
background: url("IMAGE_URL") no-repeat left top, linear-gradient(#eb01a5, #d13531);
}
The same applies to background-position, background-repeat, etc.
In order to create a rounded corner view with a gradient background and drop shadow, here's what did:
The first part is very similar to what was provided in the question, it creates a rounded rect path using CGPathAddArcToPoint as described very well in this article. Here's a picture to help me understand it:
The second part works as follows:
Enable shadowing on the graphics context, add the path that was just defined, then fill that path. You can't apply the shadow to just the path itself (paths are not part of the graphics state), so you need to fill the path in order for the shadow to appear (I suppose a stroked path might also work?). You can't simply apply the shadow to a gradient since it's not really a standard fill (see this post for more info).
Once you have a filled rounded rect that creates the shadow, you need to draw the gradient over top of that. So add the path a second time in order to set the clipping area, then draw the gradient using CGContextDrawLinearGradient. I don't think you can easily "fill" a path with a gradient like you could with the earlier standard-fill step, so instead you fill the drawing area with the gradient and then clip to the rounded rectangle area that you're interested in.
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
CGGradientRef gradient = [self normalGradient];
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGMutablePathRef outlinePath = CGPathCreateMutable();
float offset = 5.0;
float w = [self bounds].size.width;
float h = [self bounds].size.height;
CGPathMoveToPoint(outlinePath, nil, offset*2.0, offset);
CGPathAddArcToPoint(outlinePath, nil, offset, offset, offset, offset*2, offset);
CGPathAddLineToPoint(outlinePath, nil, offset, h - offset*2.0);
CGPathAddArcToPoint(outlinePath, nil, offset, h - offset, offset *2.0, h-offset, offset);
CGPathAddLineToPoint(outlinePath, nil, w - offset *2.0, h - offset);
CGPathAddArcToPoint(outlinePath, nil, w - offset, h - offset, w - offset, h - offset * 2.0, offset);
CGPathAddLineToPoint(outlinePath, nil, w - offset, offset*2.0);
CGPathAddArcToPoint(outlinePath, nil, w - offset , offset, w - offset*2.0, offset, offset);
CGPathCloseSubpath(outlinePath);
CGContextSetShadow(ctx, CGSizeMake(4,4), 3);
CGContextAddPath(ctx, outlinePath);
CGContextFillPath(ctx);
CGContextAddPath(ctx, outlinePath);
CGContextClip(ctx);
CGPoint start = CGPointMake(rect.origin.x, rect.origin.y);
CGPoint end = CGPointMake(rect.origin.x, rect.size.height);
CGContextDrawLinearGradient(ctx, gradient, start, end, 0);
CGPathRelease(outlinePath);
}
- (CGGradientRef)normalGradient
{
NSMutableArray *normalGradientLocations = [NSMutableArray arrayWithObjects:
[NSNumber numberWithFloat:0.0f],
[NSNumber numberWithFloat:1.0f],
nil];
NSMutableArray *colors = [NSMutableArray arrayWithCapacity:2];
UIColor *color = [UIColor colorWithRed:0.2745 green:0.2745 blue:0.2745 alpha:1.0];
[colors addObject:(id)[color CGColor]];
color = [UIColor colorWithRed:0.2 green:0.2 blue:0.2 alpha:1.0];
[colors addObject:(id)[color CGColor]];
NSMutableArray *normalGradientColors = colors;
int locCount = [normalGradientLocations count];
CGFloat locations[locCount];
for (int i = 0; i < [normalGradientLocations count]; i++)
{
NSNumber *location = [normalGradientLocations objectAtIndex:i];
locations[i] = [location floatValue];
}
CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
CGGradientRef normalGradient = CGGradientCreateWithColors(space, (CFArrayRef)normalGradientColors, locations);
CGColorSpaceRelease(space);
return normalGradient;
}
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