Prepare SyntheticPointerAction to handle touch actions for multiple fingers

content/browser/renderer_host/input/synthetic_pointer_action.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_pointer_action.h"
 
 #include "base/logging.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/events/latency_info.h"
 
 namespace content {
 
 SyntheticPointerAction::SyntheticPointerAction(
     const SyntheticPointerActionParams& params)
     : params_(params) {}
 
 SyntheticPointerAction::SyntheticPointerAction(
-    const SyntheticPointerActionParams& params,
-    SyntheticPointer* synthetic_pointer)
-    : params_(params), synthetic_pointer_(synthetic_pointer) {}
+    const std::vector<SyntheticPointerActionParams>& param_list,
+    SyntheticPointer* synthetic_pointer,
+    IndexMap* index_map)
+    : param_list_(param_list),
+      synthetic_pointer_(synthetic_pointer),
+      index_map_(index_map) {}
 
 SyntheticPointerAction::~SyntheticPointerAction() {}
 
 SyntheticGesture::Result SyntheticPointerAction::ForwardInputEvents(
     const base::TimeTicks& timestamp,
     SyntheticGestureTarget* target) {
-  if (params_.gesture_source_type == SyntheticGestureParams::DEFAULT_INPUT)
-    params_.gesture_source_type =
-        target->GetDefaultSyntheticGestureSourceType();
-
-  DCHECK_NE(params_.gesture_source_type, SyntheticGestureParams::DEFAULT_INPUT);
-
-  ForwardTouchOrMouseInputEvents(timestamp, target);
-  return SyntheticGesture::GESTURE_FINISHED;
+  DCHECK(synthetic_pointer_);
+  return ForwardTouchOrMouseInputEvents(timestamp, target);
 }
 
-void SyntheticPointerAction::ForwardTouchOrMouseInputEvents(
+SyntheticGesture::Result SyntheticPointerAction::ForwardTouchOrMouseInputEvents(
     const base::TimeTicks& timestamp,
     SyntheticGestureTarget* target) {
-  switch (params_.pointer_action_type()) {
-    case SyntheticPointerActionParams::PointerActionType::PRESS:
-      synthetic_pointer_->Press(params_.position().x(), params_.position().y(),
-                                target, timestamp);
-      break;
-    case SyntheticPointerActionParams::PointerActionType::MOVE:
-      synthetic_pointer_->Move(params_.index(), params_.position().x(),
-                               params_.position().y(), target, timestamp);
-      break;
-    case SyntheticPointerActionParams::PointerActionType::RELEASE:
-      synthetic_pointer_->Release(params_.index(), target, timestamp);
-      break;
-    default:
-      NOTREACHED();
-      break;
+  for (auto iter = param_list_.begin(); iter != param_list_.end(); ++iter) {

[tdresser, 2016/05/20 14:24:31]

Might as well use a range based for loop here.

Also, can the iterator be a const ref?

Can we write this something like:

for (const SyntheticPointerActionParams& params : param_list_) {}?

[lanwei, 2016/05/23 16:40:50]

Thank you for your suggestion, I will keep in mind putting const on the objects
we do not need to change.

+    SyntheticPointerActionParams params = *iter;
+    if (params.pointer_action_type() ==
+        SyntheticPointerActionParams::PointerActionType::FINISH)
+      return SyntheticGesture::POINTER_ACTION_FINISHED;
+    CHECK_GE(params.index(), 0);
+    CHECK_LT(params.index(), WebTouchEvent::touchesLengthCap);
+    switch (params.pointer_action_type()) {
+      case SyntheticPointerActionParams::PointerActionType::PRESS: {
+        int index = synthetic_pointer_->Press(
+            params.position().x(), params.position().y(), target, timestamp);
+        (*index_map_)[params.index()] = index;
+        break;
+      }
+      case SyntheticPointerActionParams::PointerActionType::MOVE:
+        CHECK_GE((*index_map_)[params.index()], 0);
+        CHECK_LT((*index_map_)[params.index()],
+                 WebTouchEvent::touchesLengthCap);
+        synthetic_pointer_->Move((*index_map_)[params.index()],
+                                 params.position().x(), params.position().y(),
+                                 target, timestamp);
+        break;
+      case SyntheticPointerActionParams::PointerActionType::RELEASE:
+        CHECK_GE((*index_map_)[params.index()], 0);
+        CHECK_LT((*index_map_)[params.index()],
+                 WebTouchEvent::touchesLengthCap);
+        synthetic_pointer_->Release((*index_map_)[params.index()], target,
+                                    timestamp);
+        break;
+      default:
+        NOTREACHED();
+        break;
+    }
   }
   synthetic_pointer_->DispatchEvent(target, timestamp);
+  return SyntheticGesture::POINTER_ACTION_PROCESSED;
 }
 
 }  // namespace content