Forward Windows touch messages to the renderer

content/browser/renderer_host/render_widget_host_view_win.cc

Index: content/browser/renderer_host/render_widget_host_view_win.cc
===================================================================
--- content/browser/renderer_host/render_widget_host_view_win.cc	(revision 108760)
+++ content/browser/renderer_host/render_widget_host_view_win.cc	(working copy)
@@ -8,11 +8,13 @@
 
 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
+#include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/threading/thread.h"
 #include "base/win/scoped_comptr.h"
 #include "base/win/scoped_gdi_object.h"
+#include "base/win/windows_version.h"
 #include "base/win/win_util.h"
 #include "base/win/windows_version.h"
 #include "base/win/wrapped_window_proc.h"
@@ -879,19 +881,25 @@
   props_.push_back(ui::SetWindowSupportsRerouteMouseWheel(m_hWnd));
 
   if (base::win::GetVersion() >= base::win::VERSION_WIN7) {
-    // Single finger panning is consistent with other windows applications.
-    const DWORD gesture_allow = GC_PAN_WITH_SINGLE_FINGER_VERTICALLY |
-                                GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;
-    const DWORD gesture_block = GC_PAN_WITH_GUTTER;
-    GESTURECONFIG gc[] = {
-        { GID_ZOOM, GC_ZOOM, 0 },
-        { GID_PAN, gesture_allow , gesture_block},
-        { GID_TWOFINGERTAP, GC_TWOFINGERTAP , 0},
-        { GID_PRESSANDTAP, GC_PRESSANDTAP , 0}
-    };
-    if (!SetGestureConfig(m_hWnd, 0, arraysize(gc), gc, sizeof(GESTURECONFIG)))
-    {
-      NOTREACHED();
+    if (CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kEnableTouchEvents)) {
+      // Enable touch events rather than gestures.
+      DCHECK(RegisterTouchWindow(m_hWnd, 0));
+    } else {
+      // Single finger panning is consistent with other windows applications.
+      const DWORD gesture_allow = GC_PAN_WITH_SINGLE_FINGER_VERTICALLY |
+                                  GC_PAN_WITH_SINGLE_FINGER_HORIZONTALLY;
+      const DWORD gesture_block = GC_PAN_WITH_GUTTER;
+      GESTURECONFIG gc[] = {
+          { GID_ZOOM, GC_ZOOM, 0 },
+          { GID_PAN, gesture_allow , gesture_block},
+          { GID_TWOFINGERTAP, GC_TWOFINGERTAP , 0},
+          { GID_PRESSANDTAP, GC_PRESSANDTAP , 0}
+      };
+      if (!SetGestureConfig(m_hWnd, 0, arraysize(gc), gc,
+          sizeof(GESTURECONFIG))) {
+        NOTREACHED();
+      }
     }
   }
 
@@ -927,6 +935,8 @@
 
   props_.reset();
 
+  UnregisterTouchWindow(m_hWnd);
+
   CleanupCompositorWindow();
 
   ResetTooltip();
@@ -1102,6 +1112,7 @@
     render_widget_host_->GotFocus();
     render_widget_host_->SetActive(true);
   }
+  FinishTouchEvent();
 }
 
 void RenderWidgetHostViewWin::OnKillFocus(HWND window) {
@@ -1109,6 +1120,7 @@
     render_widget_host_->SetActive(false);
     render_widget_host_->Blur();
   }
+  FinishTouchEvent();
 }
 
 void RenderWidgetHostViewWin::OnCaptureChanged(HWND window) {
@@ -1570,6 +1582,174 @@
   return 0;
 }
 
+void RenderWidgetHostViewWin::FinishTouchEvent() {

[ananta, 2011/11/08 20:00:25]

+1 for moving this inside a class and into a separate file.

+  if (touch_event_.touchesLength == 0)
+    return;
+
+  // Release all active touchpoints.
+  for (unsigned int i = 0; i < touch_event_.touchesLength; ++i) {
+    touch_event_.touches[i].state = WebKit::WebTouchPoint::StateReleased;
+    touch_event_.changedTouches[i].state =
+        WebKit::WebTouchPoint::StateReleased;
+  }
+  touch_event_.changedTouchesLength = touch_event_.touchesLength = 0;
+  touch_event_.type = WebKit::WebInputEvent::TouchEnd;
+  render_widget_host_->ForwardTouchEvent(touch_event_);
+  touch_event_.touchesLength = 0;
+}
+
+WebKit::WebTouchPoint* RenderWidgetHostViewWin::AddTouchPoint(
+    TOUCHINPUT* touch_input) {
+  if (touch_event_.touchesLength >= WebKit::WebTouchEvent::touchesLengthCap)
+    return NULL;
+  WebKit::WebTouchPoint* point =
+      &touch_event_.touches[touch_event_.touchesLength++];
+  point->state = WebKit::WebTouchPoint::StatePressed;
+  point->id = touch_input->dwID;
+  UpdateTouchPoint(point, touch_input);
+  return point;
+}
+
+bool RenderWidgetHostViewWin::UpdateTouchPoint(
+    WebKit::WebTouchPoint* touch_point,
+    TOUCHINPUT* touch_input) {
+  CPoint coordinates(TOUCH_COORD_TO_PIXEL(touch_input->x),
+                     TOUCH_COORD_TO_PIXEL(touch_input->y));
+  int radius_x = 0;
+  int radius_y = 0;
+  if (touch_input->dwMask & TOUCHINPUTMASKF_CONTACTAREA) {
+    radius_x = TOUCH_COORD_TO_PIXEL(touch_input->cxContact);
+    radius_y = TOUCH_COORD_TO_PIXEL(touch_input->cyContact);
+  }
+
+  // Detect and exclude stationary moves.
+  if (touch_point->state == WebKit::WebTouchPoint::StateMoved &&
+      touch_point->screenPosition.x == coordinates.x &&
+      touch_point->screenPosition.y == coordinates.y &&
+      touch_point->radiusX == radius_x &&
+      touch_point->radiusY == radius_y) {
+    touch_point->state = WebKit::WebTouchPoint::StateStationary;
+    return true;
+  }
+
+  touch_point->screenPosition.x = coordinates.x;
+  touch_point->screenPosition.y = coordinates.y;
+  GetParent().ScreenToClient(&coordinates);
+  touch_point->position.x = coordinates.x;
+  touch_point->position.y = coordinates.y;
+  touch_point->radiusX = radius_x;
+  touch_point->radiusY = radius_y;
+  touch_point->force = 1.0;
+  touch_point->rotationAngle = 0;
+  return false;
+}
+
+LRESULT RenderWidgetHostViewWin::OnTouchEvent(UINT message, WPARAM wparam,
+                                              LPARAM lparam, BOOL& handled) {
+  unsigned int touches_down = 0;
+  unsigned int touches_up = 0;
+  unsigned int touches_moved = 0;
+  // TODO(jschuh): Add support for an arbitrary number of touchpoints.
+  size_t points_count = std::min(static_cast<int>(LOWORD(wparam)),
+      static_cast<int>(WebKit::WebTouchEvent::touchesLengthCap));
+  TOUCHINPUT points[WebKit::WebTouchEvent::touchesLengthCap];
+
+  if (points_count > WebKit::WebTouchEvent::touchesLengthCap)

[ananta, 2011/11/08 20:00:25]

The std::min statement above should ensure that this never happens?

+    points_count = WebKit::WebTouchEvent::touchesLengthCap;
+  if (!points_count || !GetTouchInputInfo((HTOUCHINPUT)lparam, points_count,
+                                          points, sizeof(TOUCHINPUT))) {
+    return 0;
+  }
+  touch_event_.changedTouchesLength = 0;
+
+  for (size_t i = 0; i < points_count; i++) {
+    if (points[i].dwID == 0ul)
+      continue;
+
+    WebKit::WebTouchPoint* point = NULL;
+    for (unsigned j = 0; j < touch_event_.touchesLength; ++j) {
+      if (static_cast<DWORD>(touch_event_.touches[j].id) == points[i].dwID) {
+        point =  &touch_event_.touches[j];
+        break;
+      }
+    }
+
+    // Use a move instead if we see a down on a point we already have.
+    if (point && (points[i].dwFlags & 0x7) == TOUCHEVENTF_DOWN)

[ananta, 2011/11/08 20:00:25]

Can you add a define for the 0x7 mask?

+      points[i].dwFlags = (points[i].dwFlags & ~0x7) | TOUCHEVENTF_MOVE;
+
+    switch (points[i].dwFlags & 0x7) {
+      case TOUCHEVENTF_DOWN: {
+        if (!(point = AddTouchPoint(&points[i])))
+          continue;
+        ++touches_down;
+        break;
+      }
+
+      case TOUCHEVENTF_UP: {
+        if (!point)
+          continue;
+        point->state = WebKit::WebTouchPoint::StateReleased;
+        UpdateTouchPoint(point, &points[i]);
+        ++touches_up;
+        break;
+      }
+
+      case TOUCHEVENTF_MOVE: {
+        if (point) {
+          point->state = WebKit::WebTouchPoint::StateMoved;
+          // Don't update the message if the point didn't really move.
+          if (UpdateTouchPoint(point, &points[i]))
+            continue;
+          ++touches_moved;
+        } else {  // Add a new point if we missed the TOUCHEVENTF_DOWN
+          if (!(point = AddTouchPoint(&points[i])))
+            continue;
+          ++touches_down;
+        }
+        break;
+      }
+
+      default:
+        NOTREACHED();
+        continue;
+    }
+    touch_event_.changedTouches[touch_event_.changedTouchesLength++] = *point;
+  }
+
+  CloseTouchInputHandle((HTOUCHINPUT)lparam);
+
+  // Set the event type based on what we've received.
+  if (touches_down)
+    touch_event_.type = WebKit::WebInputEvent::TouchStart;
+  else if (touches_up)
+    touch_event_.type = WebKit::WebInputEvent::TouchEnd;
+  else if (touches_moved)
+    touch_event_.type = WebKit::WebInputEvent::TouchMove;
+  else
+    touch_event_.type = WebKit::WebInputEvent::Undefined;
+
+  // Forward the event only when there's a legitimate change.
+  if (touch_event_.changedTouchesLength)
+    render_widget_host_->ForwardTouchEvent(touch_event_);
+
+  // Clean up released touches and reset everything else to staitonary.
+  WebKit::WebTouchPoint* point = touch_event_.touches;
+  WebKit::WebTouchPoint* end =
+      &touch_event_.touches[touch_event_.touchesLength];
+  while (point < end) {
+    if (point->state == WebKit::WebTouchPoint::StateReleased) {
+      *point = *(--end);
+      --touch_event_.touchesLength;
+    } else {
+      point->state = WebKit::WebTouchPoint::StateStationary;
+      point++;
+    }
+  }
+
+  return 0;
+}
+
 LRESULT RenderWidgetHostViewWin::OnMouseActivate(UINT message,
                                                  WPARAM wparam,
                                                  LPARAM lparam,