Allow changing top controls height

cc/input/top_controls_manager.cc

 // Copyright 2013 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.
 
 #include "cc/input/top_controls_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/timing_function.h"
 #include "cc/input/top_controls_manager_client.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gfx/geometry/vector2d_f.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 namespace {
 // These constants were chosen empirically for their visually pleasant behavior.
 // Contact tedchoc@chromium.org for questions about changing these values.
 const int64 kShowHideMaxDurationMs = 200;
 }
 
 // static
 scoped_ptr<TopControlsManager> TopControlsManager::Create(
     TopControlsManagerClient* client,
-    float top_controls_height,
     float top_controls_show_threshold,
     float top_controls_hide_threshold) {
   return make_scoped_ptr(new TopControlsManager(client,
-                                                top_controls_height,
                                                 top_controls_show_threshold,
                                                 top_controls_hide_threshold));
 }
 
 TopControlsManager::TopControlsManager(TopControlsManagerClient* client,
-                                       float top_controls_height,
                                        float top_controls_show_threshold,
                                        float top_controls_hide_threshold)
     : client_(client),
       animation_direction_(NO_ANIMATION),
       permitted_state_(BOTH),
-      top_controls_height_(top_controls_height),
+      top_controls_height_(0.f),
       current_scroll_delta_(0.f),
       controls_scroll_begin_offset_(0.f),
-      top_controls_show_height_(
-          top_controls_height * top_controls_hide_threshold),
-      top_controls_hide_height_(
-          top_controls_height * (1.f - top_controls_show_threshold)),
+      top_controls_show_threshold_(top_controls_hide_threshold),
+      top_controls_hide_threshold_(top_controls_show_threshold),
       pinch_gesture_active_(false) {
   CHECK(client_);
 }
 
 TopControlsManager::~TopControlsManager() {
 }
 
 float TopControlsManager::ControlsTopOffset() {
   return client_->ControlsTopOffset();
 }
@@ skipping 94 matching lines @@
   controls_top_offset = std::min(controls_top_offset, 0.f);
 
   if (client_->ControlsTopOffset() == controls_top_offset)
     return;
 
   client_->SetControlsTopOffset(controls_top_offset);
 
   client_->DidChangeTopControlsPosition();
 }
 
+void TopControlsManager::SetTopControlsHeight(float top_controls_height) {
+  DCHECK_GE(top_controls_height, 0);
+
+  if (top_controls_height == top_controls_height_)
+    return;
+
+  ResetAnimations();
+  float top_controls_offset = client_->ControlsTopOffset();
+  top_controls_height_ = top_controls_height;
+  SetControlsTopOffset(top_controls_offset);
+  StartAnimationIfNecessary();
+}
+
 gfx::Vector2dF TopControlsManager::Animate(base::TimeTicks monotonic_time) {
   if (!top_controls_animation_ || !client_->HaveRootScrollLayer())
     return gfx::Vector2dF();
 
   base::TimeDelta time = monotonic_time - base::TimeTicks();
 
   float old_offset = client_->ControlsTopOffset();
   SetControlsTopOffset(top_controls_animation_->GetValue(time));
 
   if (IsAnimationCompleteAtTime(monotonic_time))
@@ skipping 34 matching lines @@
       EaseTimingFunction::Create()));
   animation_direction_ = direction;
   client_->DidChangeTopControlsPosition();
 }
 
 void TopControlsManager::StartAnimationIfNecessary() {
   if (client_->ControlsTopOffset() != 0
       && client_->ControlsTopOffset() != -top_controls_height_) {
     AnimationDirection show_controls = NO_ANIMATION;
 
-    if (client_->ControlsTopOffset() >= -top_controls_show_height_) {
+    float top_controls_show_height =
+        top_controls_height_ * top_controls_hide_threshold_;
+    float top_controls_hide_height =
+        top_controls_height_ * (1.f - top_controls_show_threshold_);
+    if (client_->ControlsTopOffset() >= -top_controls_show_height) {
       // If we're showing so much that the hide threshold won't trigger, show.
       show_controls = SHOWING_CONTROLS;
-    } else if (client_->ControlsTopOffset() <= -top_controls_hide_height_) {
+    } else if (client_->ControlsTopOffset() <= -top_controls_hide_height) {
       // If we're showing so little that the show threshold won't trigger, hide.
       show_controls = HIDING_CONTROLS;
     } else {
       // If we could be either showing or hiding, we determine which one to
       // do based on whether or not the total scroll delta was moving up or
       // down.
       show_controls = current_scroll_delta_ <= 0.f ?
           SHOWING_CONTROLS : HIDING_CONTROLS;
     }
 
@@ skipping 11 matching lines @@
 
   if ((animation_direction_ == SHOWING_CONTROLS && new_offset >= 0) ||
       (animation_direction_ == HIDING_CONTROLS
           && new_offset <= -top_controls_height_)) {
     return true;
   }
   return false;
 }
 
 }  // namespace cc