ui-gestures: Added some type-specific accessors to gesture-events.

Adding type-specific accessors to the gesture-events should now make the code
much more readable.

BUG=none
TEST=existing tests don't break

Review URL: https://chromiumcodereview.appspot.com/10543053

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@141997 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 174 insertions, 1 deletions

diff --git a/ui/base/gestures/gesture_sequence.cc b/ui/base/gestures/gesture_sequence.cc
index 7e3302c..586d792 100644
--- a/ui/base/gestures/gesture_sequence.cc
+++ b/ui/base/gestures/gesture_sequence.cc
@@ -771,7 +771,7 @@ void GestureSequence::AppendLongPressGestureEvent() {
       point->first_touch_position(),
       flags_,
       base::Time::FromDoubleT(point->last_touch_time()),
-      point->point_id(), 0.f, 1 << point->touch_id()));
+      0.f, 0.f, 1 << point->touch_id()));
   helper_->DispatchLongPressGestureEvent(gesture.get());
 }
 
diff --git a/ui/base/gestures/gesture_types.cc b/ui/base/gestures/gesture_types.cc
new file mode 100644
index 0000000..fbda748
--- /dev/null
+++ b/ui/base/gestures/gesture_types.cc
@@ -0,0 +1,63 @@
+// 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.
+
+#include "ui/base/gestures/gesture_types.h"
+
+namespace ui {
+
+GestureEventDetails::GestureEventDetails(ui::EventType type,
+                                         float delta_x,
+                                         float delta_y)
+    : type_(type) {
+  switch (type_) {
+    case ui::ET_GESTURE_SCROLL_UPDATE:
+      data.scroll.x = delta_x;
+      data.scroll.y = delta_y;
+      break;
+
+    case ui::ET_SCROLL_FLING_START:
+      data.velocity.x = delta_x;
+      data.velocity.y = delta_y;
+      break;
+
+    case ui::ET_GESTURE_TAP:
+      data.radius.x = delta_x;
+      data.radius.y = delta_y;
+      break;
+
+    case ui::ET_GESTURE_LONG_PRESS:
+      data.touch_id = static_cast<int>(delta_x);
+      CHECK_EQ(0.f, delta_y) << "Unknown data in delta_y for long press.";
+      break;
+
+    case ui::ET_GESTURE_BEGIN:
+    case ui::ET_GESTURE_END:
+      data.touch_points = static_cast<int>(delta_x);
+      CHECK_EQ(0.f, delta_y) << "Unknown data in delta_y for begin/end";
+      break;
+
+    case ui::ET_GESTURE_PINCH_UPDATE:
+      data.scale = delta_x;
+      CHECK_EQ(0.f, delta_y) << "Unknown data in delta_y for pinch";
+      break;
+
+    case ui::ET_GESTURE_MULTIFINGER_SWIPE:
+      data.swipe.left = delta_x < 0;
+      data.swipe.right = delta_x > 0;
+      data.swipe.up = delta_y < 0;
+      data.swipe.down = delta_y > 0;
+      break;
+
+    default:
+      data.generic.delta_x = delta_x;
+      data.generic.delta_y = delta_y;
+      if (delta_x != 0.f || delta_y != 0.f) {
+        DLOG(WARNING) << "A gesture event (" << type << ") had unknown data: ("
+                      << delta_x << "," << delta_y;
+      }
+      break;
+  }
+}
+
+}  // namespace ui
diff --git a/ui/base/gestures/gesture_types.h b/ui/base/gestures/gesture_types.h
index 902b1f0..a55914c 100644
--- a/ui/base/gestures/gesture_types.h
+++ b/ui/base/gestures/gesture_types.h
@@ -6,11 +6,121 @@
 #define UI_BASE_GESTURES_GESTURE_TYPES_H_
 #pragma once
 
+#include "base/logging.h"
 #include "base/time.h"
 #include "ui/base/events.h"
 
 namespace ui {
 
+struct UI_EXPORT GestureEventDetails {
+ public:
+  GestureEventDetails(EventType type, float delta_x, float delta_y);
+
+  float scroll_x() const {
+    CHECK_EQ(ui::ET_GESTURE_SCROLL_UPDATE, type_);
+    return data.scroll.x;
+  }
+  float scroll_y() const {
+    CHECK_EQ(ui::ET_GESTURE_SCROLL_UPDATE, type_);
+    return data.scroll.y;
+  }
+
+  float velocity_x() const {
+    CHECK_EQ(ui::ET_SCROLL_FLING_START, type_);
+    return data.velocity.x;
+  }
+  float velocity_y() const {
+    CHECK_EQ(ui::ET_SCROLL_FLING_START, type_);
+    return data.velocity.y;
+  }
+
+  float radius_x() const {
+    CHECK_EQ(ui::ET_GESTURE_TAP, type_);
+    return data.radius.x;
+  }
+  float radius_y() const {
+    CHECK_EQ(ui::ET_GESTURE_TAP, type_);
+    return data.radius.y;
+  }
+
+  int touch_id() const {
+    CHECK_EQ(ui::ET_GESTURE_LONG_PRESS, type_);
+    return data.touch_id;
+  }
+
+  int touch_points() const {
+    DCHECK(type_ == ui::ET_GESTURE_BEGIN || type_ == ui::ET_GESTURE_END);
+    return data.touch_points;
+  }
+
+  float scale() const {
+    CHECK_EQ(ui::ET_GESTURE_PINCH_UPDATE, type_);
+    return data.scale;
+  }
+
+  bool swipe_left() const {
+    CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
+    return data.swipe.left;
+  }
+  bool swipe_right() const {
+    CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
+    return data.swipe.right;
+  }
+  bool swipe_up() const {
+    CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
+    return data.swipe.up;
+  }
+  bool swipe_down() const {
+    CHECK_EQ(ui::ET_GESTURE_MULTIFINGER_SWIPE, type_);
+    return data.swipe.down;
+  }
+
+  float generic_x() const {
+    return data.generic.delta_x;
+  }
+
+  float generic_y() const {
+    return data.generic.delta_y;
+  }
+
+ private:
+  ui::EventType type_;
+  union {
+    struct {  // SCROLL delta.
+      float x;
+      float y;
+    } scroll;
+
+    float scale;  // PINCH scale.
+
+    struct {  // FLING velocity.
+      float x;
+      float y;
+    } velocity;
+
+    struct {  // TAP radius.
+      float x;
+      float y;
+    } radius;
+
+    int touch_id;  // LONG_PRESS touch-id.
+
+    int touch_points;  // Number of active touch points for BEGIN/END.
+
+    struct {  // SWIPE direction.
+      bool left;
+      bool right;
+      bool up;
+      bool down;
+    } swipe;
+
+    struct {
+      float delta_x;
+      float delta_y;
+    } generic;
+  } data;
+};
+
 // An abstract type to represent touch-events. The gesture-recognizer uses this
 // interface to communicate with the touch-events.
 class UI_EXPORT TouchEvent {