Import windows WebInputEvent factory to content

content/browser/renderer_host/input/web_input_event_builders_win.cc

+// Copyright (c) 2013 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/web_input_event_builders_win.h"
+
+#include "base/logging.h"
+
+using WebKit::WebInputEvent;
+using WebKit::WebKeyboardEvent;
+using WebKit::WebMouseEvent;
+using WebKit::WebMouseWheelEvent;
+
+namespace content {
+
+static const unsigned long kDefaultScrollLinesPerWheelDelta = 3;
+static const unsigned long kDefaultScrollCharsPerWheelDelta = 1;
+
+static bool IsKeyDown(WPARAM wparam) {
+  return (GetKeyState(wparam) & 0x8000) != 0;
+}
+
+static int GetLocationModifier(WPARAM wparam, LPARAM lparam) {
+  int modifier = 0;
+  switch (wparam) {
+  case VK_RETURN:
+    if ((lparam >> 16) & KF_EXTENDED)
+      modifier = WebInputEvent::IsKeyPad;
+    break;
+  case VK_INSERT:
+  case VK_DELETE:
+  case VK_HOME:
+  case VK_END:
+  case VK_PRIOR:
+  case VK_NEXT:
+  case VK_UP:
+  case VK_DOWN:
+  case VK_LEFT:
+  case VK_RIGHT:
+    if (!((lparam >> 16) & KF_EXTENDED))
+      modifier = WebInputEvent::IsKeyPad;
+    break;
+  case VK_NUMLOCK:
+  case VK_NUMPAD0:
+  case VK_NUMPAD1:
+  case VK_NUMPAD2:
+  case VK_NUMPAD3:
+  case VK_NUMPAD4:
+  case VK_NUMPAD5:
+  case VK_NUMPAD6:
+  case VK_NUMPAD7:
+  case VK_NUMPAD8:
+  case VK_NUMPAD9:
+  case VK_DIVIDE:
+  case VK_MULTIPLY:
+  case VK_SUBTRACT:
+  case VK_ADD:
+  case VK_DECIMAL:
+  case VK_CLEAR:
+    modifier = WebInputEvent::IsKeyPad;
+    break;
+  case VK_SHIFT:
+    if (IsKeyDown(VK_LSHIFT))
+      modifier = WebInputEvent::IsLeft;
+    else if (IsKeyDown(VK_RSHIFT))
+      modifier = WebInputEvent::IsRight;
+    break;
+  case VK_CONTROL:
+    if (IsKeyDown(VK_LCONTROL))
+      modifier = WebInputEvent::IsLeft;
+    else if (IsKeyDown(VK_RCONTROL))
+      modifier = WebInputEvent::IsRight;
+    break;
+  case VK_MENU:
+    if (IsKeyDown(VK_LMENU))
+      modifier = WebInputEvent::IsLeft;
+    else if (IsKeyDown(VK_RMENU))
+      modifier = WebInputEvent::IsRight;
+    break;
+  case VK_LWIN:
+    modifier = WebInputEvent::IsLeft;
+    break;
+  case VK_RWIN:
+    modifier = WebInputEvent::IsRight;
+    break;
+  }
+
+  DCHECK(!modifier
+         || modifier == WebInputEvent::IsKeyPad
+         || modifier == WebInputEvent::IsLeft
+         || modifier == WebInputEvent::IsRight);
+  return modifier;
+}
+
+// Loads the state for toggle keys into the event.
+static void SetToggleKeyState(WebInputEvent* event) {
+  // Low bit set from GetKeyState indicates "toggled".
+  if (::GetKeyState(VK_NUMLOCK) & 1)
+    event->modifiers |= WebInputEvent::NumLockOn;
+  if (::GetKeyState(VK_CAPITAL) & 1)
+    event->modifiers |= WebInputEvent::CapsLockOn;
+}
+
+WebKeyboardEvent WebKeyboardEventBuilder::Build(HWND hwnd, UINT message,
+                                                WPARAM wparam, LPARAM lparam) {
+  WebKeyboardEvent result;
+
+  // TODO(pkasting): http://b/1117926 Are we guaranteed that the message that
+  // GetMessageTime() refers to is the same one that we're passed in? Perhaps
+  // one of the construction parameters should be the time passed by the
+  // caller, who would know for sure.
+  result.timeStampSeconds = ::GetMessageTime() / 1000.0;
+
+  result.windowsKeyCode = static_cast<int>(wparam);
+  // Record the scan code (along with other context bits) for this key event.
+  result.nativeKeyCode = static_cast<int>(lparam);
+
+  switch (message) {
+  case WM_SYSKEYDOWN:
+    result.isSystemKey = true;
+  case WM_KEYDOWN:
+    result.type = WebInputEvent::RawKeyDown;
+    break;
+  case WM_SYSKEYUP:
+    result.isSystemKey = true;
+  case WM_KEYUP:
+    result.type = WebInputEvent::KeyUp;
+    break;
+  case WM_IME_CHAR:
+    result.type = WebInputEvent::Char;
+    break;
+  case WM_SYSCHAR:
+    result.isSystemKey = true;
+    result.type = WebInputEvent::Char;
+  case WM_CHAR:
+    result.type = WebInputEvent::Char;
+    break;
+  default:
+    NOTREACHED();
+  }
+
+  if (result.type == WebInputEvent::Char
+   || result.type == WebInputEvent::RawKeyDown) {
+    result.text[0] = result.windowsKeyCode;
+    result.unmodifiedText[0] = result.windowsKeyCode;
+  }
+  if (result.type != WebInputEvent::Char)
+    result.setKeyIdentifierFromWindowsKeyCode();
+
+  if (::GetKeyState(VK_SHIFT) & 0x8000)
+    result.modifiers |= WebInputEvent::ShiftKey;
+  if (::GetKeyState(VK_CONTROL) & 0x8000)
+    result.modifiers |= WebInputEvent::ControlKey;
+  if (::GetKeyState(VK_MENU) & 0x8000)
+    result.modifiers |= WebInputEvent::AltKey;
+  // NOTE: There doesn't seem to be a way to query the mouse button state in
+  // this case.
+
+  if (LOWORD(lparam) > 1)
+    result.modifiers |= WebInputEvent::IsAutoRepeat;
+
+  result.modifiers |= GetLocationModifier(wparam, lparam);
+
+  SetToggleKeyState(&result);
+  return result;
+}
+
+// WebMouseEvent --------------------------------------------------------------
+
+static int g_last_click_count;
+static double g_last_click_time;
+
+static LPARAM GetRelativeCursorPos(HWND hwnd) {
+  POINT pos = {-1, -1};
+  GetCursorPos(&pos);
+  ScreenToClient(hwnd, &pos);
+  return MAKELPARAM(pos.x, pos.y);
+}
+
+void ResetLastClickState() {
+  g_last_click_time = g_last_click_count = 0;
+}
+
+WebMouseEvent WebMouseEventBuilder::Build(HWND hwnd, UINT message,
+                                          WPARAM wparam, LPARAM lparam) {
+  WebMouseEvent result;
+
+  switch (message) {
+  case WM_MOUSEMOVE:
+    result.type = WebInputEvent::MouseMove;
+    if (wparam & MK_LBUTTON)
+      result.button = WebMouseEvent::ButtonLeft;
+    else if (wparam & MK_MBUTTON)
+      result.button = WebMouseEvent::ButtonMiddle;
+    else if (wparam & MK_RBUTTON)
+      result.button = WebMouseEvent::ButtonRight;
+    else
+      result.button = WebMouseEvent::ButtonNone;
+    break;
+  case WM_MOUSELEAVE:
+    result.type = WebInputEvent::MouseLeave;
+    result.button = WebMouseEvent::ButtonNone;
+    // set the current mouse position (relative to the client area of the
+    // current window) since none is specified for this event
+    lparam = GetRelativeCursorPos(hwnd);
+    break;
+  case WM_LBUTTONDOWN:
+  case WM_LBUTTONDBLCLK:
+    result.type = WebInputEvent::MouseDown;
+    result.button = WebMouseEvent::ButtonLeft;
+    break;
+  case WM_MBUTTONDOWN:
+  case WM_MBUTTONDBLCLK:
+    result.type = WebInputEvent::MouseDown;
+    result.button = WebMouseEvent::ButtonMiddle;
+    break;
+  case WM_RBUTTONDOWN:
+  case WM_RBUTTONDBLCLK:
+    result.type = WebInputEvent::MouseDown;
+    result.button = WebMouseEvent::ButtonRight;
+    break;
+  case WM_LBUTTONUP:
+    result.type = WebInputEvent::MouseUp;
+    result.button = WebMouseEvent::ButtonLeft;
+    break;
+  case WM_MBUTTONUP:
+    result.type = WebInputEvent::MouseUp;
+    result.button = WebMouseEvent::ButtonMiddle;
+    break;
+  case WM_RBUTTONUP:
+    result.type = WebInputEvent::MouseUp;
+    result.button = WebMouseEvent::ButtonRight;
+    break;
+  default:
+    NOTREACHED();
+  }
+
+  // TODO(pkasting): http://b/1117926 Are we guaranteed that the message that
+  // GetMessageTime() refers to is the same one that we're passed in? Perhaps
+  // one of the construction parameters should be the time passed by the
+  // caller, who would know for sure.
+  result.timeStampSeconds = ::GetMessageTime() / 1000.0;
+
+  // set position fields:
+
+  result.x = static_cast<short>(LOWORD(lparam));
+  result.y = static_cast<short>(HIWORD(lparam));
+  result.windowX = result.x;
+  result.windowY = result.y;
+
+  POINT global_point = { result.x, result.y };
+  ClientToScreen(hwnd, &global_point);
+
+  result.globalX = global_point.x;
+  result.globalY = global_point.y;
+
+  // calculate number of clicks:
+
+  // This differs slightly from the WebKit code in WebKit/win/WebView.cpp
+  // where their original code looks buggy.
+  static int last_click_position_x;
+  static int last_click_position_Y;
+  static WebMouseEvent::Button last_click_button = WebMouseEvent::ButtonLeft;
+
+  double current_time = result.timeStampSeconds;
+  bool cancel_previous_click =
+      (abs(last_click_position_x - result.x) >
+          (::GetSystemMetrics(SM_CXDOUBLECLK) / 2))
+      || (abs(last_click_position_x - result.y) >
+          (::GetSystemMetrics(SM_CYDOUBLECLK) / 2))
+      || ((current_time - g_last_click_time) * 1000.0 > ::GetDoubleClickTime());
+
+  if (result.type == WebInputEvent::MouseDown) {
+    if (!cancel_previous_click && (result.button == last_click_button)) {
+      ++g_last_click_count;
+    } else {
+      g_last_click_count = 1;
+      last_click_position_x = result.x;
+      last_click_position_x = result.y;
+    }
+    g_last_click_time = current_time;
+    last_click_button = result.button;
+  } else if (result.type == WebInputEvent::MouseMove
+          || result.type == WebInputEvent::MouseLeave) {
+    if (cancel_previous_click) {
+      g_last_click_count = 0;
+      last_click_position_x = 0;
+      last_click_position_x = 0;
+      g_last_click_time = 0;
+    }
+  }
+  result.clickCount = g_last_click_count;
+
+  // set modifiers:
+
+  if (wparam & MK_CONTROL)
+    result.modifiers |= WebInputEvent::ControlKey;
+  if (wparam & MK_SHIFT)
+    result.modifiers |= WebInputEvent::ShiftKey;
+  if (::GetKeyState(VK_MENU) & 0x8000)
+    result.modifiers |= WebInputEvent::AltKey;
+  if (wparam & MK_LBUTTON)
+    result.modifiers |= WebInputEvent::LeftButtonDown;
+  if (wparam & MK_MBUTTON)
+    result.modifiers |= WebInputEvent::MiddleButtonDown;
+  if (wparam & MK_RBUTTON)
+    result.modifiers |= WebInputEvent::RightButtonDown;
+
+  SetToggleKeyState(&result);
+  return result;
+}
+
+// WebMouseWheelEvent ---------------------------------------------------------
+
+WebMouseWheelEvent
+WebMouseWheelEventBuilder::Build(HWND hwnd, UINT message,
+                                 WPARAM wparam, LPARAM lparam) {
+  WebMouseWheelEvent result;
+
+  result.type = WebInputEvent::MouseWheel;
+
+  // TODO(pkasting): http://b/1117926 Are we guaranteed that the message that
+  // GetMessageTime() refers to is the same one that we're passed in? Perhaps
+  // one of the construction parameters should be the time passed by the
+  // caller, who would know for sure.
+  result.timeStampSeconds = ::GetMessageTime() / 1000.0;
+
+  result.button = WebMouseEvent::ButtonNone;
+
+  // Get key state, coordinates, and wheel delta from event.
+  typedef SHORT (WINAPI *GetKeyStateFunction)(int key);
+  GetKeyStateFunction get_key_state_func;
+  UINT key_state;
+  float wheel_delta;
+  bool horizontal_scroll = false;
+  if ((message == WM_VSCROLL) || (message == WM_HSCROLL)) {
+    // Synthesize mousewheel event from a scroll event.  This is needed to
+    // simulate middle mouse scrolling in some laptops.  Use GetAsyncKeyState
+    // for key state since we are synthesizing the input event.
+    get_key_state_func = GetAsyncKeyState;
+    key_state = 0;
+    if (get_key_state_func(VK_SHIFT))
+      key_state |= MK_SHIFT;
+    if (get_key_state_func(VK_CONTROL))
+      key_state |= MK_CONTROL;
+    // NOTE: There doesn't seem to be a way to query the mouse button state
+    // in this case.
+
+    POINT cursor_position = {0};
+    GetCursorPos(&cursor_position);
+    result.globalX = cursor_position.x;
+    result.globalY = cursor_position.y;
+
+    switch (LOWORD(wparam)) {
+      case SB_LINEUP:    // == SB_LINELEFT
+        wheel_delta = WHEEL_DELTA;
+        break;
+      case SB_LINEDOWN:  // == SB_LINERIGHT
+        wheel_delta = -WHEEL_DELTA;
+        break;
+      case SB_PAGEUP:
+        wheel_delta = 1;
+        result.scrollByPage = true;
+        break;
+      case SB_PAGEDOWN:
+        wheel_delta = -1;
+        result.scrollByPage = true;
+        break;
+      default:  // We don't supoprt SB_THUMBPOSITION or SB_THUMBTRACK here.
+        wheel_delta = 0;
+        break;
+    }
+
+    if (message == WM_HSCROLL)
+      horizontal_scroll = true;
+  } else {
+    // Non-synthesized event; we can just read data off the event.
+    get_key_state_func = ::GetKeyState;
+    key_state = GET_KEYSTATE_WPARAM(wparam);
+
+    result.globalX = static_cast<short>(LOWORD(lparam));
+    result.globalY = static_cast<short>(HIWORD(lparam));
+
+    wheel_delta = static_cast<float>(GET_WHEEL_DELTA_WPARAM(wparam));
+    if (message == WM_MOUSEHWHEEL) {
+      horizontal_scroll = true;
+      wheel_delta = -wheel_delta;  // Windows is <- -/+ ->, WebKit <- +/- ->.
+    }
+  }
+  if (key_state & MK_SHIFT)
+    horizontal_scroll = true;
+
+  // Set modifiers based on key state.
+  if (key_state & MK_SHIFT)
+    result.modifiers |= WebInputEvent::ShiftKey;
+  if (key_state & MK_CONTROL)
+    result.modifiers |= WebInputEvent::ControlKey;
+  if (get_key_state_func(VK_MENU) & 0x8000)
+    result.modifiers |= WebInputEvent::AltKey;
+  if (key_state & MK_LBUTTON)
+    result.modifiers |= WebInputEvent::LeftButtonDown;
+  if (key_state & MK_MBUTTON)
+    result.modifiers |= WebInputEvent::MiddleButtonDown;
+  if (key_state & MK_RBUTTON)
+    result.modifiers |= WebInputEvent::RightButtonDown;
+
+  SetToggleKeyState(&result);
+
+  // Set coordinates by translating event coordinates from screen to client.
+  POINT client_point = { result.globalX, result.globalY };
+  MapWindowPoints(0, hwnd, &client_point, 1);
+  result.x = client_point.x;
+  result.y = client_point.y;
+  result.windowX = result.x;
+  result.windowY = result.y;
+
+  // Convert wheel delta amount to a number of pixels to scroll.
+  //
+  // How many pixels should we scroll per line?  Gecko uses the height of the
+  // current line, which means scroll distance changes as you go through the
+  // page or go to different pages.  IE 8 is ~60 px/line, although the value
+  // seems to vary slightly by page and zoom level.  Also, IE defaults to
+  // smooth scrolling while Firefox doesn't, so it can get away with somewhat
+  // larger scroll values without feeling as jerky.  Here we use 100 px per
+  // three lines (the default scroll amount is three lines per wheel tick).
+  // Even though we have smooth scrolling, we don't make this as large as IE
+  // because subjectively IE feels like it scrolls farther than you want while
+  // reading articles.
+  static const float kScrollbarPixelsPerLine = 100.0f / 3.0f;
+  wheel_delta /= WHEEL_DELTA;
+  float scroll_delta = wheel_delta * kScrollbarPixelsPerLine;
+  if (horizontal_scroll) {
+    unsigned long scroll_chars = kDefaultScrollCharsPerWheelDelta;
+    SystemParametersInfo(SPI_GETWHEELSCROLLCHARS, 0, &scroll_chars, 0);
+    // TODO(pkasting): Should probably have a different multiplier
+    // scrollbarPixelsPerChar here.
+    scroll_delta *= static_cast<float>(scroll_chars);
+  } else {
+    unsigned long scroll_lines = kDefaultScrollLinesPerWheelDelta;
+    SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &scroll_lines, 0);
+    if (scroll_lines == WHEEL_PAGESCROLL)
+      result.scrollByPage = true;
+    if (!result.scrollByPage)
+      scroll_delta *= static_cast<float>(scroll_lines);
+  }
+
+  // Set scroll amount based on above calculations.  WebKit expects positive
+  // deltaY to mean "scroll up" and positive deltaX to mean "scroll left".
+  if (horizontal_scroll) {
+    result.deltaX = scroll_delta;
+    result.wheelTicksX = wheel_delta;
+  } else {
+    result.deltaY = scroll_delta;
+    result.wheelTicksY = wheel_delta;
+  }
+
+  return result;
+}
+
+}  // namespace content