Upstream iOS UI utilities.

ios/chrome/browser/ui/uikit_ui_util.h

+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_UIKIT_UI_UTIL_H_
+#define IOS_CHROME_BROWSER_UI_UIKIT_UI_UTIL_H_
+
+#include <CoreGraphics/CoreGraphics.h>
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+// UI Util containing functions that require UIKit.
+
+enum { FONT_HELVETICA, FONT_HELVETICA_NEUE, FONT_HELVETICA_NEUE_LIGHT };
+
+// Utility function to set the |element|'s accessibility label to the localized
+// message corresponding to |idsAccessibilityLabel| and its accessibility
+// identifier to |englishUiAutomationName|.
+// Call SetA11yLabelAndUiAutomationName() if |element| is accessible and its
+// a11y label should be localized.
+// By convention |englishUiAutomationName| must be equal to the English
+// localized string corresponding to |idsAccessibilityLabel|.
+// |englishUiAutomationName| is the name used in JavaScript UI Automation test
+// scripts to identify the |element|.
+void SetA11yLabelAndUiAutomationName(UIView* element,
+                                     int idsAccessibilityLabel,
+                                     NSString* englishUiAutomationName);
+
+// Sets the given |button|'s width to exactly fit its image and text.  Does not
+// modify the button's height.
+void GetSizeButtonWidthToFit(UIButton* button);
+
+// Translates the given |view|'s frame.  Sets a new frame instead of applying a
+// transform to the existing frame.
+void TranslateFrame(UIView* view, UIOffset offset);
+
+// Returns a UIFont. |fontFace| is one of the defined enumerated values
+// to avoid spelling mistakes.
+UIFont* GetUIFont(int fontFace, bool isBold, CGFloat fontSize);
+
+// Adds a border shadow around |view|.
+void AddBorderShadow(UIView* view, CGFloat offset, UIColor* color);
+
+// Adds a rounded-rectangle border shadow around a view.
+void AddRoundedBorderShadow(UIView* view, CGFloat radius, UIColor* color);
+
+// Captures and returns an autoreleased rendering of the |view|.
+// The |view| is assumed to be opaque and the returned image does
+// not have an alpha channel. The scale parameter is used as a scale factor
+// for the rendering context. Using 0.0 as scale will result in the device's
+// main screen scale to be used.
+UIImage* CaptureView(UIView* view, CGFloat scale);
+
+// Converts input image and returns a grey scaled version.
+UIImage* GreyImage(UIImage* image);
+
+// Returns the color that should be used for the background of all Settings
+// pages.
+UIColor* GetSettingsBackgroundColor();
+
+// Returns the color used as the main color for primary action buttons.
+UIColor* GetPrimaryActionButtonColor();
+
+// Returns an UIColor with |rgb| and |alpha|. The caller should pass the RGB
+// value in hexadecimal as this is the typical way they are provided by UX.
+// For example a call to |UIColorFromRGB(0xFF7D40, 1.0)| returns an orange
+// UIColor object.
+inline UIColor* UIColorFromRGB(int rgb, CGFloat alpha = 1.0) {
+  return [UIColor colorWithRed:((CGFloat)((rgb & 0xFF0000) >> 16)) / 255.0
+                         green:((CGFloat)((rgb & 0x00FF00) >> 8)) / 255.0
+                          blue:((CGFloat)(rgb & 0x0000FF)) / 255.0
+                         alpha:alpha];
+}
+
+// Returns an image resized to |targetSize|. It first calculate the projection
+// by calling CalculateProjection() and then create a new image of the desired
+// size and project the correct subset of the originla image onto it.
+//
+// Image interpolation level for resizing is set to kCGInterpolationDefault.
+//
+// The resize always preserves the scale of the original image.
+UIImage* ResizeImage(UIImage* image,
+                     CGSize targetSize,
+                     BOOL preserveAspectRatio,
+                     BOOL trimToFit);
+
+// Returns a slightly blurred image darkened enough to provide contrast for
+// white text to be readable.
+UIImage* DarkenImage(UIImage* image);
+
+// Applies various effects to an image. This method can apply a blur over a
+// |radius|, superimpose a |tintColor| (an alpha of 0.6 on the color is a good
+// approximation to look like iOS tint colors) or saturate the image colors by
+// applying a |saturationDeltaFactor| (negative to desaturate, positive to
+// saturate). The optional |maskImage| is used to limit the effect of the blur
+// and/or saturation to a portion of the image.
+UIImage* BlurImage(UIImage* image,
+                   CGFloat blurRadius,
+                   UIColor* tintColor,
+                   CGFloat saturationDeltaFactor,
+                   UIImage* maskImage);
+
+// Returns the interface orientation of the app.
+UIInterfaceOrientation GetInterfaceOrientation();
+
+// Returns the height of the keyboard in the current orientation.
+CGFloat CurrentKeyboardHeight(NSValue* keyboardFrameValue);
+
+// Create 1x1px image from |color|.
+UIImage* ImageWithColor(UIColor* color);
+
+// Returns a circular image of width |width| based on |image| scaled up or
+// down. If the source image is not square, the image is first cropped.
+UIImage* CircularImageFromImage(UIImage* image, CGFloat width);
+
+// Returns the linear interpolated color from |firstColor| to |secondColor| by
+// the given |fraction|. Requires that both colors are in RGB or monochrome
+// color space. |fraction| is a decimal value between 0.0 and 1.0.
+UIColor* InterpolateFromColorToColor(UIColor* firstColor,
+                                     UIColor* secondColor,
+                                     CGFloat fraction);
+
+// Applies all |constraints| to all views in |subviewsDictionary| in the
+// superview |parentView|.
+void ApplyVisualConstraints(NSArray* constraints,
+                            NSDictionary* subviewsDictionary,
+                            UIView* parentView);
+
+// Adds a constraint that |subview| is center aligned horizontally in
+// |parentView|.
+// |subview| must be a subiew of |parentView|.
+void AddSameCenterXConstraint(UIView* parentView, UIView* subview);
+
+// Adds a constraint that |subview1| and |subview2| are center aligned
+// vertically on |parentView|.
+// |subview1| and |subview2| must be subiews of |parentView|.
+void AddSameCenterYConstraint(UIView* parentView,
+                              UIView* subview1,
+                              UIView* subview2);
+
+#endif  // IOS_CHROME_BROWSER_UI_UIKIT_UI_UTIL_H_