Implement touch selection for RWHVV.

content/renderer/render_view.cc

 // Copyright (c) 2011 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/renderer/render_view.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 342 matching lines @@
       target_url_status_(TARGET_NONE),
       ALLOW_THIS_IN_INITIALIZER_LIST(pepper_delegate_(this)),
       ALLOW_THIS_IN_INITIALIZER_LIST(accessibility_method_factory_(this)),
       ALLOW_THIS_IN_INITIALIZER_LIST(cookie_jar_(this)),
       geolocation_dispatcher_(NULL),
       speech_input_dispatcher_(NULL),
       device_orientation_dispatcher_(NULL),
       accessibility_ack_pending_(false),
       p2p_socket_dispatcher_(NULL),
       devtools_agent_(NULL),
-      session_storage_namespace_id_(session_storage_namespace_id) {
+      session_storage_namespace_id_(session_storage_namespace_id),
+      selection_ack_pending_(false) {
   routing_id_ = routing_id;
   if (opener_id != MSG_ROUTING_NONE)
     opener_id_ = opener_id;
 
   webwidget_ = WebView::create(this);
 
   if (counter) {
     shared_popup_counter_ = counter;
     shared_popup_counter_->data++;
     decrement_shared_popup_at_destruction_ = true;
@@ skipping 232 matching lines @@
     IPC_MESSAGE_HANDLER(ViewMsg_Redo, OnRedo)
     IPC_MESSAGE_HANDLER(ViewMsg_Cut, OnCut)
     IPC_MESSAGE_HANDLER(ViewMsg_Copy, OnCopy)
 #if defined(OS_MACOSX)
     IPC_MESSAGE_HANDLER(ViewMsg_CopyToFindPboard, OnCopyToFindPboard)
 #endif
     IPC_MESSAGE_HANDLER(ViewMsg_Paste, OnPaste)
     IPC_MESSAGE_HANDLER(ViewMsg_Replace, OnReplace)
     IPC_MESSAGE_HANDLER(ViewMsg_Delete, OnDelete)
     IPC_MESSAGE_HANDLER(ViewMsg_SelectAll, OnSelectAll)
+    IPC_MESSAGE_HANDLER(ViewMsg_SelectRect, OnSelectRect)
     IPC_MESSAGE_HANDLER(ViewMsg_CopyImageAt, OnCopyImageAt)
     IPC_MESSAGE_HANDLER(ViewMsg_ExecuteEditCommand, OnExecuteEditCommand)
     IPC_MESSAGE_HANDLER(ViewMsg_Find, OnFind)
     IPC_MESSAGE_HANDLER(ViewMsg_StopFinding, OnStopFinding)
     IPC_MESSAGE_HANDLER(ViewMsg_FindReplyACK, OnFindReplyAck)
     IPC_MESSAGE_HANDLER(ViewMsg_Zoom, OnZoom)
     IPC_MESSAGE_HANDLER(ViewMsg_SetZoomLevel, OnSetZoomLevel)
     IPC_MESSAGE_HANDLER(ViewMsg_SetZoomLevelForLoadingURL,
                         OnSetZoomLevelForLoadingURL)
     IPC_MESSAGE_HANDLER(ViewMsg_SetPageEncoding, OnSetPageEncoding)
@@ skipping 345 matching lines @@
 }
 
 void RenderView::OnSelectAll() {
   if (!webview())
     return;
 
   webview()->focusedFrame()->executeCommand(
       WebString::fromUTF8("SelectAll"));
 }
 
+void RenderView::OnSelectRect(const gfx::Point& start, const gfx::Point& end) {

[darin (slow to review), 2011/08/04 18:15:57]

I wonder... since the IPC is called SelectRect, shouldn't the parameter just be
a gfx::Rect?  why are you using two points?

[varunjain, 2011/08/04 19:25:22]

mostly because the selected region may not be a rectangle (such as most
selection on a webpage). the IPC is called SelectRect because of the naming of
the function upstream in the call heirarchy. I can change the name of the IPC to
SelectRange if this is unacceptable. 

+  if (!webview())
+    return;
+
+  selection_ack_pending_ = true;
+  webview()->focusedFrame()->selectRange(start, end);
+  selection_ack_pending_ = false;
+}
+
 void RenderView::OnSetInitialFocus(bool reverse) {
   if (!webview())
     return;
   webview()->setInitialFocus(reverse);
 }
 
 #if defined(OS_MACOSX)
 void RenderView::OnSetInLiveResize(bool in_live_resize) {
     if (!webview())
         return;
@@ skipping 515 matching lines @@
 bool RenderView::isSelectTrailingWhitespaceEnabled() {
 #if defined(OS_WIN)
   return true;
 #else
   return false;
 #endif
 }
 
 void RenderView::didChangeSelection(bool is_empty_selection) {
 #if defined(OS_POSIX)
-  if (!handling_input_event_)
+  if (!handling_input_event_ && !selection_ack_pending_)
       return;
+  selection_ack_pending_ = false;

[darin (slow to review), 2011/08/04 18:15:57]

this seems like the wrong name for this member variable.  we normally use the
"ack" notion for IPC acknowledgements.  this is not that.  handling_select_rect_
might be a better name.

also, it is not clear to me why you want to do this only for OS_POSIX.  the
SelectRect IPC is not restricted to OS_POSIX.

[varunjain, 2011/08/04 19:25:22]

Done
the SelectionChanged IPC is only handled for OS_POSIX. For others its a no-op.
SelectRect is only sent for touchui

 
   if (is_empty_selection) {
     last_selection_.clear();
   } else {
     // Sometimes we get repeated didChangeSelection calls from webkit when
     // the selection hasn't actually changed. We don't want to report these
     // because it will cause us to continually claim the X clipboard.
     WebFrame* frame = webview()->focusedFrame();
     const std::string& this_selection = frame->selectionAsText().utf8();
     if (this_selection == last_selection_)
       return;
     last_selection_ = this_selection;
   }
 
   ui::Range range(ui::Range::InvalidRange());
   size_t location, length;
   if (webview()->caretOrSelectionRange(&location, &length)) {
     range.set_start(location);
     range.set_end(location + length);
   }
-  Send(new ViewHostMsg_SelectionChanged(routing_id_, last_selection_, range));
+
+  WebKit::WebPoint start, end;
+  webview()->selectionRange(start, end);
+
+  // Webkit gives an offset of 1 between start and end even if there is no
+  // selection. So we need to check against that.
+  // TODO(varunjain): remove this check once that is fixed.

[darin (slow to review), 2011/08/04 18:15:57]

instead of adding this hack here, wouldn't it be better to write a webkit patch
first?

[varunjain, 2011/08/04 19:25:22]

I need to first check with clang team as they were the original authors of the
selectionRange() implementation. Perhaps they want to keep it that way. Hence
the TODO.

+  gfx::Point p1, p2;
+  if (std::abs(start.x - end.x) > 1 || std::abs(start.y - end.y) > 1) {
+    gfx::Point scroll_offset = GetScrollOffset();

[darin (slow to review), 2011/08/04 18:15:57]

it seems like you are trying to correct for scroll offset.  does that imply that
WebView::selectionRange() does not return coordinates in the view port space? 
if so, then your code here is failing to take into account iframes that might be
scrolled.  it is pretty difficult to adjust for scroll offset from outside of
Webkit.  maybe we need to revise the selectionRange() API?

[varunjain, 2011/08/04 19:25:22]

selectionRange API may need to be revised. I intended this CL to contain the
boiler plate code and basic requirements to get touch selection to work (IPC
communication etc.). With this CL, I have text selection on simple webpages
working fine. I intend to refine the code to work with complex webpages in
subsequent CLs.

+    p1.SetPoint(start.x + scroll_offset.x(), start.y + scroll_offset.y());
+    p2.SetPoint(end.x + scroll_offset.x(), end.y + scroll_offset.y());
+  }
+  // TODO(varunjain): add other hooks for SelectionChanged.
+  Send(new ViewHostMsg_SelectionChanged(routing_id_, last_selection_, range,
+      p1, p2));

[darin (slow to review), 2011/08/04 18:15:57]

nit: please indent "p1, p2));" so that p1 starts at the same column as
routing_id_.

[varunjain, 2011/08/04 19:25:22]

Done.

 #endif  // defined(OS_POSIX)
 }
 
 void RenderView::didExecuteCommand(const WebString& command_name) {
   const std::string& name = UTF16ToUTF8(command_name);
   if (StartsWithASCII(name, "Move", true) ||
       StartsWithASCII(name, "Insert", true) ||
       StartsWithASCII(name, "Delete", true))
     return;
   RenderThread::current()->Send(
@@ skipping 2883 matching lines @@
 }
 #endif
 
 void RenderView::OnContextMenuClosed(
     const webkit_glue::CustomContextMenuContext& custom_context) {
   if (custom_context.is_pepper_menu)
     pepper_delegate_.OnContextMenuClosed(custom_context);
   else
     context_menu_node_.reset();
 }