Constrained window sheet controller (test patch)

chrome/browser/ui/cocoa/constrained_window/constrained_window_animation.mm

+// Copyright (c) 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 "chrome/browser/ui/cocoa/constrained_window/constrained_window_animation.h"
+
+#include "base/file_path.h"
+#include "base/location.h"
+#import "base/mac/foundation_util.h"
+#include "base/native_library.h"
+#include "ui/base/animation/tween.h"
+
+// The window animations in this file use private APIs as described here:
+// http://goo.gl/CK43l
+// There are two important things to keep in mind when modifying this file:
+// - For most operations the origin of the coordinate system is top left.
+// - Perspective and shear transformations get clipped if they are bigger
+//   then the window size. This does not seem to apply to scale transformations.
+
+// Length of the animation in seconds.
+const NSTimeInterval kSAnimationDuraiton = 0.18;
+
+// The number of pixels above the final destination to animate from.
+const CGFloat kShowHideVerticalOffset = 20;
+
+// Scale the window by this percent when animating.
+const CGFloat kShowHideScalePercent = 0.99;
+
+// Size of the perspective effect as a percent of the window width.
+const CGFloat kShowHidePerspectivePercent = 0.04;
+
+namespace {
+
+typedef int CGSWindow;
+typedef int CGSConnection;
+typedef struct {
+  float x;
+  float y;
+} MeshPoint;
+typedef struct {
+    MeshPoint local;
+    MeshPoint global;
+} CGPointWarp;
+
+// These are private APIs that we look up at runtime.
+typedef CGSConnection (*CGSDefaultConnectionFunc)();
+typedef CGError (*CGSSetWindowTransformFunc)(
+    const CGSConnection cid,
+    const CGSWindow wid,
+    CGAffineTransform transform);
+typedef CGError (*CGSSetWindowWarpFunc)(
+    const CGSConnection cid,
+    const CGSWindow wid,
+    int w,
+    int h,
+    CGPointWarp* mesh);
+typedef CGError (*CGSSetWindowAlphaFunc)(
+    const CGSConnection cid,
+    const CGSWindow wid,
+    float alpha);
+
+CGSDefaultConnectionFunc g_CGSDefaultConnection;
+CGSSetWindowTransformFunc g_CGSSetWindowTransform;
+CGSSetWindowWarpFunc g_CGSSetWindowWarp;
+CGSSetWindowAlphaFunc g_CGSSetWindowAlpha;
+
+// Look up private Window APIs. Returns true on success.
+bool InitializeWindowAPIs() {
+  bool should_initialize = true;
+  if (should_initialize) {
+    should_initialize = false;
+    CFBundleRef bundle =
+        CFBundleGetBundleWithIdentifier(CFSTR("com.apple.CoreGraphics"));
+    if (!bundle)
+      return false;
+
+    NSArray* names = [NSArray arrayWithObjects:
+        @"_CGSDefaultConnection",
+        @"CGSSetWindowTransform",
+        @"CGSSetWindowWarp",
+        @"CGSSetWindowAlpha",
+        nil];
+    void* functions[[names count]];
+    CFBundleGetFunctionPointersForNames(
+        bundle, base::mac::NSToCFCast(names), functions);
+
+    g_CGSDefaultConnection =
+        reinterpret_cast<CGSDefaultConnectionFunc>(functions[0]);
+    g_CGSSetWindowTransform =
+        reinterpret_cast<CGSSetWindowTransformFunc>(functions[1]);
+    g_CGSSetWindowWarp = reinterpret_cast<CGSSetWindowWarpFunc>(functions[2]);
+    g_CGSSetWindowAlpha = reinterpret_cast<CGSSetWindowAlphaFunc>(functions[3]);
+  }
+  return g_CGSDefaultConnection && g_CGSSetWindowTransform &&
+         g_CGSSetWindowWarp && g_CGSSetWindowAlpha;
+}
+
+// Get the window location relative to the top left of the main screen.
+// Most Cocoa APIs use a coordinate system where the screen origin is the
+// bottom left. The various CGSSetWindow* APIs use a coordinate system where
+// the screen origin is the top left.
+NSPoint GetCGSWindowScreenOrigin(NSWindow* window) {
+  NSArray *screens = [NSScreen screens];
+  if ([screens count] == 0)
+    return NSZeroPoint;
+  NSScreen* main_screen = [screens objectAtIndex:0];
+
+  NSRect window_frame = [window frame];
+  NSRect screen_frame = [main_screen frame];
+  return NSMakePoint(NSMinX(window_frame),
+                     NSHeight(screen_frame) - NSMaxY(window_frame));
+}
+
+// Set the transparency of the window.
+void SetWindowAlpha(NSWindow* window, float alpha) {
+  CGSConnection cid = g_CGSDefaultConnection();
+  g_CGSSetWindowAlpha(cid, [window windowNumber], alpha);
+}
+
+// Scales the window and translates it so that it stays centered relative
+// to its original position.
+void SetWindowScale(NSWindow* window, float scale) {
+  CGFloat scale_delta = 1.0 - scale;
+  CGFloat cur_scale = 1.0 + scale_delta;
+  CGAffineTransform transform =
+      CGAffineTransformMakeScale(cur_scale, cur_scale);
+
+  // Translate the window to keep it centered at the original location.
+  NSSize window_size = [window frame].size;
+  CGFloat scale_offset_x = window_size.width * (1 - cur_scale) / 2.0;
+  CGFloat scale_offset_y = window_size.height * (1 - cur_scale) / 2.0;
+
+  NSPoint origin = GetCGSWindowScreenOrigin(window);
+  CGFloat new_x = -origin.x + scale_offset_x;
+  CGFloat new_y = -origin.y + scale_offset_y;
+  transform = CGAffineTransformTranslate(transform, new_x, new_y);
+
+  CGSConnection cid = g_CGSDefaultConnection();
+  g_CGSSetWindowTransform(cid, [window windowNumber], transform);
+}
+
+// Unsets any window warp that may have been previously applied.
+// Window warp prevents other effects such as CGSSetWindowTransform from
+// being applied.
+void ClearWindowWarp(NSWindow* window) {
+  CGSConnection cid = g_CGSDefaultConnection();
+  g_CGSSetWindowWarp(cid, [window windowNumber], 0, 0, NULL);
+}
+
+// Applies various transformations using a warp effect. The window is
+// translated vertically by |y_offset|. The window is scaled |by |scale| and
+// translated so that the it remains centered relative to its original position.
+// Finally, perspective is effect is applied by shrinking the top of the window.
+void SetWindowWarp(NSWindow* window,
+                   float y_offset,
+                   float scale,
+                   float perspective_offset) {
+  NSRect win_rect = [window frame];
+  win_rect.origin = NSZeroPoint;
+  NSRect screen_rect = win_rect;
+  screen_rect.origin = GetCGSWindowScreenOrigin(window);
+
+  // Apply a vertical translate.
+  screen_rect.origin.y -= y_offset;
+
+  // Apply a scale and translate to keep the window centered.
+  screen_rect.origin.x += (NSWidth(win_rect) - NSWidth(screen_rect)) / 2.0;
+  screen_rect.origin.y += (NSHeight(win_rect) - NSHeight(screen_rect)) / 2.0;
+
+  // A 2 x 2 mesh that maps each corner of the window to a location in screen
+  // coordinates. Note that the origin of the coordinate system is top, left.
+  CGPointWarp mesh[2][2] = {
+    {
+      {  // Top left.
+        {NSMinX(win_rect), NSMinY(win_rect)},
+        {NSMinX(screen_rect) + perspective_offset, NSMinY(screen_rect)},
+      },
+      {  // Top right.
+        {NSMaxX(win_rect), NSMinY(win_rect)},
+        {NSMaxX(screen_rect) - perspective_offset, NSMinY(screen_rect)},
+      }
+    },
+    {
+      {  // Bottom left.
+        {NSMinX(win_rect), NSMaxY(win_rect)},
+        {NSMinX(screen_rect), NSMaxY(screen_rect)},
+      },
+      {  // Bottom right.
+        {NSMaxX(win_rect), NSMaxY(win_rect)},
+        {NSMaxX(screen_rect), NSMaxY(screen_rect)},
+      }
+    },
+  };
+
+  CGSConnection cid = g_CGSDefaultConnection();
+  g_CGSSetWindowWarp(cid, [window windowNumber], 2, 2, &(mesh[0][0]));
+}
+
+// Sets the varoius effects that are a part of the Show/Hide animation.
+// Value is a number between 0 and 1 where 0 means the window is completely
+// hidden and 1 means the window is fully visible.
+void UpdateWindowShowHideAnimationState(NSWindow* window, CGFloat value) {
+  CGFloat inverse_value = 1.0 - value;
+
+  SetWindowAlpha(window, value);
+  CGFloat y_offset = kShowHideVerticalOffset * inverse_value;
+  CGFloat scale = 1.0 - (1.0 - kShowHideScalePercent) * inverse_value;
+  CGFloat perspective_offset =
+      ([window frame].size.width * kShowHidePerspectivePercent) * inverse_value;
+
+  SetWindowWarp(window, y_offset, scale, perspective_offset);
+}
+
+}
+
+@interface ConstrainedWindowAnimationBase ()
+// Subclasses should override these to update the window state for the current
+// animation value.
+- (void)setWindowStateForStart;
+- (void)setWindowStateForValue:(float)value;
+- (void)setWindowStateForEnd;
+@end
+
+@implementation ConstrainedWindowAnimationBase
+
+- (id)initWithWindow:(NSWindow*)window {
+  if (!InitializeWindowAPIs()) {
+    [self release];
+    return nil;
+  }
+
+  if ((self = [self initWithDuration:kSAnimationDuraiton
+                      animationCurve:NSAnimationEaseInOut])) {
+    window_.reset([window retain]);
+    [self setAnimationBlockingMode:NSAnimationNonblocking];
+    [self setWindowStateForStart];
+  }
+  return self;
+}
+
+- (void)stopAnimation {
+  [super stopAnimation];
+  [self setWindowStateForEnd];
+  if ([[self delegate] respondsToSelector:@selector(animationDidEnd:)])
+    [[self delegate] animationDidEnd:self];
+}
+
+- (void)setCurrentProgress:(NSAnimationProgress)progress {
+  [super setCurrentProgress:progress];
+
+  if (progress >= 1.0) {
+    [self setWindowStateForEnd];
+    return;
+  }
+  [self setWindowStateForValue:[self currentValue]];
+}
+
+- (void)setWindowStateForStart {
+  // Subclasses can optionally override this method.
+}
+
+- (void)setWindowStateForValue:(float)value {
+  // Subclasses must override this method.
+  NOTREACHED();
+}
+
+- (void)setWindowStateForEnd {
+  // Subclasses can optionally override this method.
+}
+
+@end
+
+
+@implementation ConstrainedWindowAnimationShow
+
+- (void)setWindowStateForStart {
+    SetWindowAlpha(window_, 0.0);
+}
+
+- (void)setWindowStateForValue:(float)value {
+  UpdateWindowShowHideAnimationState(window_, value);
+}
+
+- (void)setWindowStateForEnd {
+  SetWindowAlpha(window_, 1.0);
+  ClearWindowWarp(window_);
+}
+
+@end
+
+@implementation ConstrainedWindowAnimationHide
+
+- (void)setWindowStateForValue:(float)value {
+  UpdateWindowShowHideAnimationState(window_, 1.0 - value);
+}
+
+- (void)setWindowStateForEnd {
+  SetWindowAlpha(window_, 0.0);
+  ClearWindowWarp(window_);
+}
+
+@end
+
+@implementation ConstrainedWindowAnimationPulse
+
+// Sets the window scale based on the animation progress.
+- (void)setWindowStateForValue:(float)value {
+  struct KeyFrame {
+    float value;
+    float scale;
+  };
+  KeyFrame frames[] = {
+    {0.00, 1.0},
+    {0.40, 1.02},
+    {0.60, 1.02},
+    {1.00, 1.0},
+  };
+
+  CGFloat scale = 1;
+  int count = sizeof(frames) / sizeof(*frames);
+  for (int i = count - 1; i >= 0; --i) {
+    if (value >= frames[i].value) {
+      CGFloat delta = frames[i + 1].value - frames[i].value;
+      CGFloat percent = (value - frames[i].value) / delta;
+      scale = ui::Tween::ValueBetween(percent,
+                                      frames[i].scale,
+                                      frames[i + 1].scale);
+      break;
+    }
+  }
+
+  SetWindowScale(window_, scale);
+}
+
+- (void)setWindowStateForEnd {
+  SetWindowScale(window_, 1.0);
+}
+
+@end