Make TextFields reroute mouse wheel messages

chrome/views/controls/text_field.cc

 // Copyright (c) 2009 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 "chrome/views/controls/text_field.h"
 
 #include <atlbase.h>
 #include <atlapp.h>
 #include <atlcrack.h>
 #include <atlctrls.h>
 #include <tom.h>  // For ITextDocument, a COM interface to CRichEditCtrl
 #include <vsstyle.h>
 
 #include "base/gfx/native_theme.h"
 #include "base/scoped_clipboard_writer.h"
 #include "base/string_util.h"
 #include "base/win_util.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/clipboard_service.h"
 #include "chrome/common/gfx/insets.h"
 #include "chrome/common/l10n_util.h"
 #include "chrome/common/l10n_util_win.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/win_util.h"
 #include "chrome/views/controls/hwnd_view.h"
 #include "chrome/views/controls/menu/menu.h"
+#include "chrome/views/focus/focus_util_win.h"
 #include "chrome/views/widget/widget.h"
 #include "grit/generated_resources.h"
 #include "skia/ext/skia_utils_win.h"
 
 using gfx::NativeTheme;
 
 namespace views {
 
 static const int kDefaultEditStyle = WS_CHILD | WS_VISIBLE;
 
@@ skipping 39 matching lines @@
     MESSAGE_HANDLER_EX(WM_IME_CHAR, OnImeChar)
     MESSAGE_HANDLER_EX(WM_IME_STARTCOMPOSITION, OnImeStartComposition)
     MESSAGE_HANDLER_EX(WM_IME_COMPOSITION, OnImeComposition)
     MSG_WM_KEYDOWN(OnKeyDown)
     MSG_WM_LBUTTONDBLCLK(OnLButtonDblClk)
     MSG_WM_LBUTTONDOWN(OnLButtonDown)
     MSG_WM_LBUTTONUP(OnLButtonUp)
     MSG_WM_MBUTTONDOWN(OnNonLButtonDown)
     MSG_WM_MOUSEMOVE(OnMouseMove)
     MSG_WM_MOUSELEAVE(OnMouseLeave)
+    MESSAGE_HANDLER_EX(WM_MOUSEWHEEL, OnMouseWheel)
     MSG_WM_NCCALCSIZE(OnNCCalcSize)
     MSG_WM_NCPAINT(OnNCPaint)
     MSG_WM_RBUTTONDOWN(OnNonLButtonDown)
     MSG_WM_PASTE(OnPaste)
     MSG_WM_SYSCHAR(OnSysChar)  // WM_SYSxxx == WM_xxx with ALT down
     MSG_WM_SYSKEYDOWN(OnKeyDown)
   END_MSG_MAP()
 
   // Menu::Delegate
   virtual bool IsCommandEnabled(int id) const;
@@ skipping 27 matching lines @@
   void OnCut();
   void OnDestroy();
   LRESULT OnImeChar(UINT message, WPARAM wparam, LPARAM lparam);
   LRESULT OnImeStartComposition(UINT message, WPARAM wparam, LPARAM lparam);
   LRESULT OnImeComposition(UINT message, WPARAM wparam, LPARAM lparam);
   void OnKeyDown(TCHAR key, UINT repeat_count, UINT flags);
   void OnLButtonDblClk(UINT keys, const CPoint& point);
   void OnLButtonDown(UINT keys, const CPoint& point);
   void OnLButtonUp(UINT keys, const CPoint& point);
   void OnMouseLeave();
+  LRESULT OnMouseWheel(UINT message, WPARAM w_param, LPARAM l_param);
   void OnMouseMove(UINT keys, const CPoint& point);
   int OnNCCalcSize(BOOL w_param, LPARAM l_param);
   void OnNCPaint(HRGN region);
   void OnNonLButtonDown(UINT keys, const CPoint& point);
   void OnPaste();
   void OnSysChar(TCHAR ch, UINT repeat_count, UINT flags);
 
   // Helper function for OnChar() and OnKeyDown() that handles keystrokes that
   // could change the text in the edit.
   void HandleKeystroke(UINT message, TCHAR key, UINT repeat_count, UINT flags);
@@ skipping 476 matching lines @@
   OnBeforePossibleChange();
   DefWindowProc(WM_LBUTTONUP, keys,
                 MAKELPARAM(ClipXCoordToVisibleText(point.x, false), point.y));
   OnAfterPossibleChange();
 }
 
 void TextField::Edit::OnMouseLeave() {
   SetContainsMouse(false);
 }
 
+LRESULT TextField::Edit::OnMouseWheel(UINT message,
+                                      WPARAM w_param, LPARAM l_param) {
+  // Reroute the mouse-wheel to the window under the mouse pointer if
+  // applicable.
+  if (views::RerouteMouseWheel(m_hWnd, w_param, l_param))
+    return 0;
+  return DefWindowProc(message, w_param, l_param);;
+}
+
 void TextField::Edit::OnMouseMove(UINT keys, const CPoint& point) {
   SetContainsMouse(true);
   // Clamp the selection to the visible text so the user can't drag to select
   // the "phantom newline".  In theory we could achieve this by clipping the X
   // coordinate, but in practice the edit seems to behave nondeterministically
   // with similar sequences of clipped input coordinates fed to it.  Maybe it's
   // reading the mouse cursor position directly?
   //
   // This solution has a minor visual flaw, however: if there's a visible
   // cursor at the edge of the text (only true when there's no selection),
@@ skipping 504 matching lines @@
 
   COLORREF bg_color;
   if (!use_default_background_color_)
     bg_color = skia::SkColorToCOLORREF(background_color_);
   else
     bg_color = GetSysColor(read_only_ ? COLOR_3DFACE : COLOR_WINDOW);
   edit_->SetBackgroundColor(bg_color);
 }
 
 }  // namespace views