_UIBackdropView is a private class in UIKit.framework (iOS 7.0+), a subclass of UIView, which is used for the popular blur effects.
It uses a CABackdropLayer with a gaussianBlur CAFilter.[1]
To create the _UIBackdropView, you need to create its settings first. Here's all settings class available in iOS 7.0
Class name | Style number | Comments/Used by |
---|---|---|
_UIBackdropViewSettingsBlur | 0 | Common blurring |
_UIBackdropViewSettingsUltraLight | 2010 | Some alert views in Settings app & many white UIs |
_UIBackdropViewSettingsLight | 2020 | |
_UIBackdropViewSettingsDark | 2030 | iOS 7 Notification Center (?) |
_UIBackdropViewSettingsDarkLow | 2039 | |
_UIBackdropViewSettingsColored | 2040 | |
_UIBackdropViewSettingsUltraDark | 2050 | |
_UIBackdropViewSettingsAdaptiveLight | 2060 | iOS 7 Control Center |
_UIBackdropViewSettingsSemiLight | 2070 | |
_UIBackdropViewSettingsUltraColored | 2080 |
There are 2 ways to create the settings object
_UIBackdropViewSettings *settings = (_UIBackdropViewSettings *)[[[_UIBackdropViewSettingsSemiLight alloc] init] autorelease];
// or
_UIBackdropViewSettings *settings = [_UIBackdropViewSettings settingsForStyle:2070];
Creating _UIBackdropView (Blur view) object
_UIBackdropViewSettings *settings = [_UIBackdropViewSettings settingsForStyle:2060];
_UIBackdropView *blurView = [[_UIBackdropView alloc] initWithFrame:CGRectZero
autosizesToFitSuperview:YES settings:settings];
[someView addSubview:backView];
[blurView release];
Blur Quality
There are only two qualities available.
- low
- default (Assumed to be "medium")
You can set it like this:
[blurView setBlurQuality:@"low"];
Tinting blur view
[blurView setRequiresColorStatistics:YES];
[blurView setColorTint:[UIColor cyanColor]];
[blurView setColorTintAlpha:0.8];
[blurView setColorTintMaskAlpha:0.7];
References