Add touchpad speed factor setting to Chrome OS touchpad settings page...

chrome/browser/chromeos/touchpad.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/browser/chromeos/touchpad.h"
 
 #include <stdlib.h>
 #include <string>
 #include <vector>
 
@@ skipping 12 matching lines @@
 void RunnableMethodTraits<Touchpad>::RetainCallee(
     Touchpad* remover) {
 }
 template<>
 void RunnableMethodTraits<Touchpad>::ReleaseCallee(
     Touchpad* remover) {
 }
 
 // static
 void Touchpad::RegisterUserPrefs(PrefService* prefs) {
-  prefs->RegisterBooleanPref(prefs::kTapToClickEnabled, true);
+  prefs->RegisterBooleanPref(prefs::kTapToClickEnabled, false);
   prefs->RegisterBooleanPref(prefs::kVertEdgeScrollEnabled, true);
+  prefs->RegisterRealPref(prefs::kTouchpadSpeedFactor, 0.5);
 }
 
 void Touchpad::Init(PrefService* prefs) {
   tap_to_click_enabled_.Init(prefs::kTapToClickEnabled, prefs, this);
   vert_edge_scroll_enabled_.Init(prefs::kVertEdgeScrollEnabled, prefs, this);
+  speed_factor_.Init(prefs::kTouchpadSpeedFactor, prefs, this);
 
   // Initialize touchpad settings to what's saved in user preferences.
   SetTapToClick();
   SetVertEdgeScroll();
+  SetSpeedFactor();
 }
 
 void Touchpad::Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details) {
   if (type == NotificationType::PREF_CHANGED)
     NotifyPrefChanged(Details<std::wstring>(details).ptr());
 }
 
 void Touchpad::NotifyPrefChanged(const std::wstring* pref_name) {
   if (!pref_name || *pref_name == prefs::kTapToClickEnabled)
     SetTapToClick();
   if (!pref_name || *pref_name == prefs::kVertEdgeScrollEnabled)
     SetVertEdgeScroll();
+  if (!pref_name || *pref_name == prefs::kTouchpadSpeedFactor)
+    SetSpeedFactor();
 }
 
 void Touchpad::SetSynclientParam(const std::string& param,
                                  const std::string& value) {
   // If not running on the file thread, then re-run on the file thread.
   if (!ChromeThread::CurrentlyOn(ChromeThread::FILE)) {
     base::Thread* file_thread = g_browser_process->file_thread();
     if (file_thread)
       file_thread->message_loop()->PostTask(FROM_HERE,
           NewRunnableMethod(this, &Touchpad::SetSynclientParam, param, value));
@@ skipping 21 matching lines @@
 
 void Touchpad::SetVertEdgeScroll() {
   // To disable vertical edge scroll, we set VertEdgeScroll to 0. Vertical edge
   // scroll lets you use the right edge of the touchpad to control the movement
   // of the vertical scroll bar.
   if (vert_edge_scroll_enabled_.GetValue())
     SetSynclientParam("VertEdgeScroll", "1");
   else
     SetSynclientParam("VertEdgeScroll", "0");
 }
+
+void Touchpad::SetSpeedFactor() {
+  // To set speed factor, we use MinSpeed. Both MaxSpeed and AccelFactor are 0.
+  // So MinSpeed will control the speed of the cursor with respect to the
+  // touchpad movement and there will not be any acceleration.
+  // We enforce that MinSpeed is between 0.01 and 1.00.
+  double value = speed_factor_.GetValue();
+  if (value < 0.01)
+    value = 0.01;
+  if (value > 1.0)
+    value = 1.0;
+  SetSynclientParam("MinSpeed", StringPrintf("%f", value));
+}