Adding synthetic touch/mouse drag [Part1]

content/browser/renderer_host/input/synthetic_smooth_drag_gesture.cc

+// Copyright 2015 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 "content/browser/renderer_host/input/synthetic_smooth_drag_gesture.h"
+
+namespace content {
+
+SyntheticSmoothDragGesture::SyntheticSmoothDragGesture(
+    const SyntheticSmoothDragGestureParams& params)
+    : drag_setup_(false), params_(params) {

[picksi, 2015/02/19 11:50:18]

nit:drag_initialized might be a clearer name?

[ssid, 2015/02/20 10:58:54]

Acknowledged.

+}
+
+SyntheticSmoothDragGesture::~SyntheticSmoothDragGesture() {
+}
+
+SyntheticGesture::Result SyntheticSmoothDragGesture::ForwardInputEvents(
+    const base::TimeTicks& timestamp,
+    SyntheticGestureTarget* target) {
+  if (drag_setup_ == false) {
+    SyntheticGestureParams::GestureSourceType gesture_type =
+        params_.gesture_source_type;
+    if (gesture_type == SyntheticGestureParams::DEFAULT_INPUT)
+      gesture_type = target->GetDefaultSyntheticGestureSourceType();
+
+    if (gesture_type == SyntheticGestureParams::TOUCH_INPUT ||
+        gesture_type == SyntheticGestureParams::MOUSE_INPUT)

[Sami, 2015/02/19 11:59:05]

Use braces for multi-line if statements.

[ssid, 2015/02/20 10:58:54]

Done.

+      move_gesture_.reset(new SyntheticSmoothMoveGesture(
+          GetInputSourceType(gesture_type), params_.start_point,
+          params_.distances, params_.speed_in_pixels_s, true));

[picksi, 2015/02/19 11:50:18]

Would pixels_per_second be a better name than speed_in_pixels_s? The trailing _s
looks like a typo!

[Sami, 2015/02/19 11:59:05]

nit: please make prevent_fling a named variable to make this a little easier to
read. Does it make sense to always set it to true for drags?

[ssid, 2015/02/20 10:58:54]

It was the name given in the previous versions. I just followed
synthetic_smooth_scroll_gesture_params.h

[ssid, 2015/02/20 10:58:54]

IMO, Drag is dragging the screen, rather than fling which makes sense in swipe.
So, it is always true.

+    else
+      return SyntheticGesture::GESTURE_SOURCE_TYPE_NOT_IMPLEMENTED;
+
+    drag_setup_ = true;
+  }

[picksi, 2015/02/19 11:50:18]

Can you move the initialization into its own init() function. The
ForwardInputEvents() function should only contain code related to forwarding
input events, not initialization code!

[ssid, 2015/02/20 10:58:54]

Done.

+  return move_gesture_->ForwardInputEvents(timestamp, target);
+}
+
+SyntheticSmoothMoveGesture::InputType
+SyntheticSmoothDragGesture::GetInputSourceType(
+    SyntheticGestureParams::GestureSourceType gesture_source_type) {
+  if (gesture_source_type == SyntheticGestureParams::MOUSE_INPUT)
+    return SyntheticSmoothMoveGesture::MOUSE_CLICK;
+  else
+    return SyntheticSmoothMoveGesture::TOUCH_INPUT;
+}
+
+}  // namespace content