Pointer/hover media query support: platform-dependent changes

ui/android/java/src/org/chromium/ui/base/TouchDevice.java

 // Copyright 2014 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.
 
 package org.chromium.ui.base;
 
 import android.content.Context;
 import android.content.pm.PackageManager;
+import android.view.InputDevice;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 
 /**
- * Simple proxy to let us query the touch device from C++
+ * Simple proxy for querying input device properties from C++.
  */
 @JNINamespace("ui")
 public class TouchDevice {
 
     /**
      * Static methods only so make constructor private.
      */
     private TouchDevice() { }
 
     /**
-     * Returns the number of supported touch points.
-     *
      * @return Maximum supported touch points.
      */
     @CalledByNative
     private static int maxTouchPoints(Context context) {
-        // Android only tells us if the device belongs to a "Touchscreen Class"
-        // which only guarantees a minimum number of touch points. Be
-        // conservative and return the minimum, checking membership from the
-        // highest class down.
+        // Android only tells us if the device belongs to a "Touchscreen Class" which only
+        // guarantees a minimum number of touch points. Be conservative and return the minimum,
+        // checking membership from the highest class down.
+
         if (context.getPackageManager().hasSystemFeature(
                 PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH_JAZZHAND)) {
             return 5;
         } else if (context.getPackageManager().hasSystemFeature(
                 PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH_DISTINCT)) {
             return 2;
         } else if (context.getPackageManager().hasSystemFeature(
                 PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH)) {
             return 2;
         } else if (context.getPackageManager().hasSystemFeature(
                 PackageManager.FEATURE_TOUCHSCREEN)) {
             return 1;
         } else {
             return 0;
         }
     }
+
+    /**
+     * @return the pointer-types supported by the device, as the union (bitwise OR) of PointerType
+     *         bits.
+     */
+    @CalledByNative
+    private static int availablePointerTypes(Context context) {
+        int pointerTypesVal = 0;
+
+        for (int deviceId : InputDevice.getDeviceIds()) {
+            int sources = InputDevice.getDevice(deviceId).getSources();
+
+            if (hasSource(sources, InputDevice.SOURCE_MOUSE)
+                    || hasSource(sources, InputDevice.SOURCE_STYLUS)
+                    || hasSource(sources, InputDevice.SOURCE_TOUCHPAD)
+                    || hasSource(sources, InputDevice.SOURCE_TRACKBALL)) {
+                pointerTypesVal |= PointerType.FINE;
+            } else if (hasSource(sources, InputDevice.SOURCE_TOUCHSCREEN)) {
+                pointerTypesVal |= PointerType.COARSE;
+            } else {
+                // The remaining InputDevice sources:
+                // SOURCE_DPAD, SOURCE_GAMEPAD, SOURCE_JOYSTICK, SOURCE_KEYBOARD,
+                // SOURCE_TOUCH_NAVIGATION, SOURCE_UNKNOWN
+                pointerTypesVal |= PointerType.NONE;
+            }
+        }
+
+        return pointerTypesVal;
+    }
+
+    /**
+     * @return the hover-types supported by the device, as the union (bitwise OR) of HoverType bits.
+     */
+    @CalledByNative
+    private static int availableHoverTypes(Context context) {
+        int hoverTypesVal = 0;
+
+        for (int deviceId : InputDevice.getDeviceIds()) {
+            int sources = InputDevice.getDevice(deviceId).getSources();
+
+            if (hasSource(sources, InputDevice.SOURCE_MOUSE)
+                    || hasSource(sources, InputDevice.SOURCE_TOUCHPAD)
+                    || hasSource(sources, InputDevice.SOURCE_TRACKBALL)) {
+                hoverTypesVal |= HoverType.HOVER;
+            } else if (hasSource(sources, InputDevice.SOURCE_STYLUS)
+                    || hasSource(sources, InputDevice.SOURCE_TOUCHSCREEN)) {
+                hoverTypesVal |= HoverType.ON_DEMAND;
+            } else {
+                // The remaining InputDevice sources:
+                // SOURCE_DPAD, SOURCE_GAMEPAD, SOURCE_JOYSTICK,
+                // SOURCE_KEYBOARD, SOURCE_TOUCH_NAVIGATION, SOURCE_UNKNOWN
+                hoverTypesVal |= HoverType.NONE;
+            }
+        }
+
+        return hoverTypesVal;
+    }
+
+    private static boolean hasSource(int sources, int inputDeviceSource) {
+        return (sources & inputDeviceSource) == inputDeviceSource;
+    }
 }