Upstream iOS UI utilities.

ios/chrome/browser/ui/uikit_ui_util.mm

+// 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.
+
+#import "ios/chrome/browser/ui/uikit_ui_util.h"
+
+#import <Accelerate/Accelerate.h>
+#import <Foundation/Foundation.h>
+#import <QuartzCore/QuartzCore.h>
+#import <UIKit/UIKit.h>
+#include <cmath>
+
+#include "base/logging.h"
+#include "base/ios/ios_util.h"
+#include "base/mac/foundation_util.h"
+#include "ios/chrome/browser/ui/ui_util.h"
+#include "ios/chrome/browser/ui/ui_util.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/l10n/l10n_util_mac.h"
+#include "ui/gfx/scoped_cg_context_save_gstate_mac.h"
+#include "ui/ios/uikit_util.h"
+
+namespace {
+
+// Linearly interpolate between |a| and |b| by fraction |f|. Satisfies
+// |lerp(a,b,0) == a| and |lerp(a,b,1) == b|.

[sdefresne, 2015/01/13 15:19:25]

nit: s/lerp/Lerp/g

+CGFloat Lerp(CGFloat a, CGFloat b, CGFloat fraction) {
+  return a * (1.0f - fraction) + b * fraction;
+}
+
+// Gets the RGBA components from a UIColor in RBG or monochrome color space.
+void GetRGBA(UIColor* color, CGFloat* r, CGFloat* g, CGFloat* b, CGFloat* a) {
+  switch (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor))) {
+    case kCGColorSpaceModelRGB: {
+      BOOL success = [color getRed:r green:g blue:b alpha:a];
+      DCHECK(success);
+      return;
+    }
+    case kCGColorSpaceModelMonochrome: {
+      const size_t componentsCount =
+          CGColorGetNumberOfComponents(color.CGColor);
+      DCHECK(componentsCount == 1 || componentsCount == 2);
+      const CGFloat* components = CGColorGetComponents(color.CGColor);
+      *r = components[0];
+      *g = components[0];
+      *b = components[0];
+      *a = componentsCount == 1 ? 1 : components[1];
+      return;
+    }
+    default:
+      NOTREACHED() << "Unsupported color space.";
+      return;
+  }
+}
+
+}  // namespace
+
+void SetA11yLabelAndUiAutomationName(UIView* element,
+                                     int idsAccessibilityLabel,
+                                     NSString* englishUiAutomationName) {
+  [element setAccessibilityLabel:l10n_util::GetNSString(idsAccessibilityLabel)];
+  [element setAccessibilityIdentifier:englishUiAutomationName];
+}
+
+void GetSizeButtonWidthToFit(UIButton* button) {
+  // Resize the button's width to fit the new text, but keep the original
+  // height. sizeToFit appears to ignore the image size, so re-add the size of
+  // the button's image to the frame width.
+  CGFloat buttonHeight = [button frame].size.height;
+  CGFloat imageWidth = [[button imageView] frame].size.width;
+  [button sizeToFit];
+  CGRect newFrame = [button frame];
+  newFrame.size.height = buttonHeight;
+  newFrame.size.width += imageWidth;
+  [button setFrame:newFrame];
+}
+
+void TranslateFrame(UIView* view, UIOffset offset) {
+  if (!view)
+    return;
+
+  CGRect frame = [view frame];
+  frame.origin.x = frame.origin.x + offset.horizontal;
+  frame.origin.y = frame.origin.y + offset.vertical;
+  [view setFrame:frame];
+}
+
+UIFont* GetUIFont(int fontFace, bool isBold, CGFloat fontSize) {
+  NSString* fontFaceName;
+  switch (fontFace) {
+    case FONT_HELVETICA:
+      fontFaceName = isBold ? @"Helvetica-Bold" : @"Helvetica";
+      break;
+    case FONT_HELVETICA_NEUE:
+      fontFaceName = isBold ? @"HelveticaNeue-Bold" : @"HelveticaNeue";
+      break;
+    case FONT_HELVETICA_NEUE_LIGHT:
+      // FONT_HELVETICA_NEUE_LIGHT does not support Bold.
+      DCHECK(!isBold);
+      fontFaceName = @"HelveticaNeue-Light";
+      break;
+    default:
+      NOTREACHED();
+      fontFaceName = @"Helvetica";
+      break;
+  }
+  return [UIFont fontWithName:fontFaceName size:fontSize];
+}
+
+void AddBorderShadow(UIView* view, CGFloat offset, UIColor* color) {
+  CGRect rect = CGRectInset(view.bounds, -offset, -offset);
+  CGPoint waypoints[] = {
+      CGPointMake(rect.origin.x, rect.origin.y),
+      CGPointMake(rect.origin.x, rect.origin.y + rect.size.height),
+      CGPointMake(rect.origin.x + rect.size.width,
+                  rect.origin.y + rect.size.height),
+      CGPointMake(rect.origin.x + rect.size.width, rect.origin.y),
+      CGPointMake(rect.origin.x, rect.origin.y)};
+  int numberOfWaypoints = sizeof(waypoints) / sizeof(waypoints[0]);
+  CGMutablePathRef outline = CGPathCreateMutable();
+  CGPathAddLines(outline, NULL, waypoints, numberOfWaypoints);
+  view.layer.shadowColor = [color CGColor];
+  view.layer.shadowOpacity = 1.0;
+  view.layer.shadowOffset = CGSizeZero;
+  view.layer.shadowPath = outline;
+  CGPathRelease(outline);
+}
+
+// TODO(pkl): The implementation of this has some duplicated code with
+// AddBorderShadow and ToolsPopupView newPathForRect:withRadius:withArrow:.
+// There is an opportunity to refactor them into a common shadow library.
+void AddRoundedBorderShadow(UIView* view, CGFloat radius, UIColor* color) {
+  CGRect rect = view.bounds;
+  CGMutablePathRef path = CGPathCreateMutable();
+  CGFloat minX = CGRectGetMinX(rect);
+  CGFloat midX = CGRectGetMidX(rect);
+  CGFloat maxX = CGRectGetMaxX(rect);
+  CGFloat minY = CGRectGetMinY(rect);
+  CGFloat midY = CGRectGetMidY(rect);
+  CGFloat maxY = CGRectGetMaxY(rect);
+  CGPathMoveToPoint(path, NULL, minX, midY);
+  CGPathAddArcToPoint(path, NULL, minX, minY, midX, minY, radius);
+  CGPathAddArcToPoint(path, NULL, maxX, minY, maxX, midY, radius);
+  CGPathAddArcToPoint(path, NULL, maxX, maxY, midX, maxY, radius);
+  CGPathAddArcToPoint(path, NULL, minX, maxY, minX, midY, radius);
+  CGPathCloseSubpath(path);
+  view.layer.shadowColor = [color CGColor];
+  view.layer.shadowOpacity = 1.0;
+  view.layer.shadowRadius = radius;
+  view.layer.shadowOffset = CGSizeZero;
+  view.layer.shadowPath = path;
+  view.layer.borderWidth = 0.0;
+  CGPathRelease(path);
+}
+
+UIImage* CaptureView(UIView* view, CGFloat scale) {
+  UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES /* opaque */,
+                                         scale);
+  CGContext* context = UIGraphicsGetCurrentContext();
+  [view.layer renderInContext:context];
+  UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+  return image;
+}
+
+UIImage* GreyImage(UIImage* image) {
+  DCHECK(image);
+  // Grey images are always non-retina to improve memory performance.
+  UIGraphicsBeginImageContextWithOptions(image.size, YES, 1.0);
+  CGRect greyImageRect = CGRectMake(0, 0, image.size.width, image.size.height);
+  [image drawInRect:greyImageRect blendMode:kCGBlendModeLuminosity alpha:1.0];
+  UIImage* greyImage = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+  return greyImage;
+}
+
+UIColor* GetPrimaryActionButtonColor() {
+  return UIColorFromRGB(0x2d6ada, 1.0);
+}
+
+UIColor* GetSettingsBackgroundColor() {
+  CGFloat rgb = 237.0 / 255.0;
+  return [UIColor colorWithWhite:rgb alpha:1];
+}
+
+UIImage* ResizeImage(UIImage* image,
+                     CGSize targetSize,
+                     BOOL preserveAspectRatio,
+                     BOOL trimToFit) {
+  CGSize revisedTargetSize;
+  CGRect projectTo;
+
+  CalculateProjection([image size], targetSize, preserveAspectRatio, trimToFit,
+                      revisedTargetSize, projectTo);
+
+  if (CGRectEqualToRect(projectTo, CGRectZero))
+    return nil;
+
+  // Resize photo. Use UIImage drawing methods because they respect
+  // UIImageOrientation as opposed to CGContextDrawImage().
+  UIGraphicsBeginImageContextWithOptions(revisedTargetSize, NO, image.scale);
+  [image drawInRect:projectTo];
+  UIImage* resizedPhoto = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+  return resizedPhoto;
+}
+
+UIImage* DarkenImage(UIImage* image) {
+  UIColor* tintColor = [UIColor colorWithWhite:0.22 alpha:0.6];
+  return BlurImage(image,
+                   3.0,  // blurRadius,
+                   tintColor,
+                   1.8,  // saturationDeltaFactor
+                   nil);
+}
+
+UIImage* BlurImage(UIImage* image,
+                   CGFloat blurRadius,
+                   UIColor* tintColor,
+                   CGFloat saturationDeltaFactor,
+                   UIImage* maskImage) {
+  // This code is heavily inspired by the UIImageEffect sample project,
+  // presented at WWDC and available from Apple.
+  DCHECK(image.size.width >= 1 && image.size.height >= 1);
+  DCHECK(image.CGImage);
+  DCHECK(!maskImage || maskImage.CGImage);
+
+  CGRect imageRect = {CGPointZero, image.size};
+  UIImage* effectImage = nil;
+
+  BOOL hasBlur = blurRadius > __FLT_EPSILON__;
+  BOOL hasSaturationChange = fabs(saturationDeltaFactor - 1.) > __FLT_EPSILON__;
+  if (hasBlur || hasSaturationChange) {
+    UIGraphicsBeginImageContextWithOptions(image.size,
+                                           NO,  // opaque.
+                                           [[UIScreen mainScreen] scale]);
+    CGContextRef effectInContext = UIGraphicsGetCurrentContext();
+    CGContextScaleCTM(effectInContext, 1.0, -1.0);
+    CGContextTranslateCTM(effectInContext, 0, -image.size.height);
+    CGContextDrawImage(effectInContext, imageRect, image.CGImage);
+
+    vImage_Buffer effectInBuffer;
+    effectInBuffer.data = CGBitmapContextGetData(effectInContext);
+    effectInBuffer.width = CGBitmapContextGetWidth(effectInContext);
+    effectInBuffer.height = CGBitmapContextGetHeight(effectInContext);
+    effectInBuffer.rowBytes = CGBitmapContextGetBytesPerRow(effectInContext);
+
+    UIGraphicsBeginImageContextWithOptions(image.size,
+                                           NO,  // opaque.
+                                           [[UIScreen mainScreen] scale]);
+    CGContextRef effectOutContext = UIGraphicsGetCurrentContext();
+    vImage_Buffer effectOutBuffer;
+    effectOutBuffer.data = CGBitmapContextGetData(effectOutContext);
+    effectOutBuffer.width = CGBitmapContextGetWidth(effectOutContext);
+    effectOutBuffer.height = CGBitmapContextGetHeight(effectOutContext);
+    effectOutBuffer.rowBytes = CGBitmapContextGetBytesPerRow(effectOutContext);
+
+    // Those are swapped as effects are applied.
+    vImage_Buffer* inBuffer = &effectInBuffer;
+    vImage_Buffer* outBuffer = &effectOutBuffer;
+
+    if (hasBlur) {
+      // A description of how to compute the box kernel width from the Gaussian
+      // radius (aka standard deviation) appears in the SVG spec:
+      // http://www.w3.org/TR/SVG/filters.html#feGaussianBlurElement
+      //
+      // For larger values of 's' (s >= 2.0), an approximation can be used:
+      // Three successive box-blurs build a piece-wise quadratic convolution
+      // kernel, which approximates the Gaussian kernel to within roughly 3%.
+      //
+      // let d = floor(s * 3*sqrt(2*pi)/4 + 0.5)
+      //
+      // ... if d is odd, use three box-blurs of size 'd', centered on the
+      // output pixel.
+      //
+      CGFloat inputRadius = blurRadius * [[UIScreen mainScreen] scale];
+      NSUInteger radius = floor(inputRadius * 3. * sqrt(2 * M_PI) / 4 + 0.5);
+      if (radius % 2 != 1) {
+        // force radius to be odd so that the three box-blur methodology works.
+        radius += 1;
+      }
+      for (int i = 0; i < 3; ++i) {
+        vImageBoxConvolve_ARGB8888(inBuffer,            // src.
+                                   outBuffer,           // dst.
+                                   NULL,                // tempBuffer.
+                                   0,                   // srcOffsetToROI_X.
+                                   0,                   // srcOffsetToROI_Y
+                                   radius,              // kernel_height
+                                   radius,              // kernel_width
+                                   0,                   // backgroundColor
+                                   kvImageEdgeExtend);  // flags
+        vImage_Buffer* temp = inBuffer;
+        inBuffer = outBuffer;
+        outBuffer = temp;
+      }
+    }
+    if (hasSaturationChange) {
+      CGFloat s = saturationDeltaFactor;
+      CGFloat floatingPointSaturationMatrix[] = {
+          0.0722 + 0.9278 * s,  0.0722 - 0.0722 * s,  0.0722 - 0.0722 * s,  0,
+          0.7152 - 0.7152 * s,  0.7152 + 0.2848 * s,  0.7152 - 0.7152 * s,  0,
+          0.2126 - 0.2126 * s,  0.2126 - 0.2126 * s,  0.2126 + 0.7873 * s,  0,
+          0,                    0,                    0,  1 };
+      const int32_t divisor = 256;
+      NSUInteger matrixSize = sizeof(floatingPointSaturationMatrix) /
+                              sizeof(floatingPointSaturationMatrix[0]);
+      int16_t saturationMatrix[matrixSize];
+      for (NSUInteger i = 0; i < matrixSize; ++i) {
+        saturationMatrix[i] =
+            (int16_t)roundf(floatingPointSaturationMatrix[i] * divisor);
+      }
+      vImageMatrixMultiply_ARGB8888(inBuffer, outBuffer, saturationMatrix,
+                                    divisor, NULL, NULL, kvImageNoFlags);
+    }
+    if (outBuffer == &effectOutBuffer)
+      effectImage = UIGraphicsGetImageFromCurrentImageContext();
+    UIGraphicsEndImageContext();
+
+    if (!effectImage)
+      effectImage = UIGraphicsGetImageFromCurrentImageContext();
+    UIGraphicsEndImageContext();
+  }
+
+  // Set up output context.
+  UIGraphicsBeginImageContextWithOptions(image.size,
+                                         NO,  // opaque
+                                         [[UIScreen mainScreen] scale]);
+  CGContextRef outputContext = UIGraphicsGetCurrentContext();
+  CGContextScaleCTM(outputContext, 1.0, -1.0);
+  CGContextTranslateCTM(outputContext, 0, -image.size.height);
+
+  // Draw base image.
+  CGContextDrawImage(outputContext, imageRect, image.CGImage);
+
+  // Draw effect image.
+  if (effectImage) {
+    gfx::ScopedCGContextSaveGState context(outputContext);
+    if (maskImage)
+      CGContextClipToMask(outputContext, imageRect, maskImage.CGImage);
+    CGContextDrawImage(outputContext, imageRect, effectImage.CGImage);
+  }
+
+  // Add in color tint.
+  if (tintColor) {
+    gfx::ScopedCGContextSaveGState context(outputContext);
+    CGContextSetFillColorWithColor(outputContext, tintColor.CGColor);
+    CGContextFillRect(outputContext, imageRect);
+  }
+
+  // Output image is ready.
+  UIImage* outputImage = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+
+  return outputImage;
+}
+
+UIInterfaceOrientation GetInterfaceOrientation() {
+  return [[UIApplication sharedApplication] statusBarOrientation];
+}
+
+CGFloat CurrentKeyboardHeight(NSValue* keyboardFrameValue) {
+  CGSize keyboardSize = [keyboardFrameValue CGRectValue].size;
+  if (base::ios::IsRunningOnIOS8OrLater()) {
+    return keyboardSize.height;
+  } else {
+    return IsPortrait() ? keyboardSize.height : keyboardSize.width;
+  }
+}
+
+UIImage* ImageWithColor(UIColor* color) {
+  CGRect rect = CGRectMake(0, 0, 1, 1);
+  UIGraphicsBeginImageContext(rect.size);
+  CGContextRef context = UIGraphicsGetCurrentContext();
+  CGContextSetFillColorWithColor(context, [color CGColor]);
+  CGContextFillRect(context, rect);
+  UIImage* image = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+  return image;
+}
+
+UIImage* CircularImageFromImage(UIImage* image, CGFloat width) {
+  CGRect frame =
+      CGRectMakeAlignedAndCenteredAt(width / 2.0, width / 2.0, width);
+
+  UIGraphicsBeginImageContextWithOptions(frame.size, NO, 0.0);
+  CGContextRef context = UIGraphicsGetCurrentContext();
+
+  CGContextBeginPath(context);
+  CGContextAddEllipseInRect(context, frame);
+  CGContextClosePath(context);
+  CGContextClip(context);
+
+  CGFloat scaleX = frame.size.width / image.size.width;
+  CGFloat scaleY = frame.size.height / image.size.height;
+  CGFloat scale = std::max(scaleX, scaleY);
+  CGContextScaleCTM(context, scale, scale);
+
+  [image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
+
+  image = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+
+  return image;
+}
+
+UIColor* InterpolateFromColorToColor(UIColor* firstColor,
+                                     UIColor* secondColor,
+                                     CGFloat fraction) {
+  DCHECK_LE(0.0, fraction);
+  DCHECK_LE(fraction, 1.0);
+  CGFloat r1, r2, g1, g2, b1, b2, a1, a2;
+  GetRGBA(firstColor, &r1, &g1, &b1, &a1);
+  GetRGBA(secondColor, &r2, &g2, &b2, &a2);
+  return [UIColor colorWithRed:Lerp(r1, r2, fraction)
+                         green:Lerp(g1, g2, fraction)
+                          blue:Lerp(b1, b2, fraction)
+                         alpha:Lerp(a1, a2, fraction)];
+}
+
+void ApplyVisualConstraints(NSArray* constraints,
+                            NSDictionary* subviewsDictionary,
+                            UIView* parentView) {
+  for (NSString* constraint in constraints) {
+    DCHECK([constraint isKindOfClass:[NSString class]]);
+    [parentView
+        addConstraints:[NSLayoutConstraint
+                           constraintsWithVisualFormat:constraint
+                                               options:0
+                                               metrics:nil
+                                                 views:subviewsDictionary]];
+  }
+}
+
+void AddSameCenterXConstraint(UIView* parentView, UIView* subview) {
+  DCHECK_EQ(parentView, [subview superview]);
+  [parentView addConstraint:[NSLayoutConstraint
+                                constraintWithItem:subview
+                                         attribute:NSLayoutAttributeCenterX
+                                         relatedBy:NSLayoutRelationEqual
+                                            toItem:parentView
+                                         attribute:NSLayoutAttributeCenterX
+                                        multiplier:1
+                                          constant:0]];
+}
+
+void AddSameCenterYConstraint(UIView* parentView,
+                              UIView* subview1,
+                              UIView* subview2) {
+  DCHECK_EQ(parentView, [subview1 superview]);
+  DCHECK_EQ(parentView, [subview2 superview]);
+  DCHECK_NE(subview1, subview2);
+  [parentView addConstraint:[NSLayoutConstraint
+                                constraintWithItem:subview1
+                                         attribute:NSLayoutAttributeCenterY
+                                         relatedBy:NSLayoutRelationEqual
+                                            toItem:subview2
+                                         attribute:NSLayoutAttributeCenterY
+                                        multiplier:1
+                                          constant:0]];
+}