[Remoting Android] Move feedback type to radius logic out of DesktopView

remoting/android/java/src/org/chromium/chromoting/InputFeedbackRadiusMapper.java

+// Copyright 2016 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.chromoting;
+
+import android.view.View;
+
+/**
+ * Helper class for mapping a feedback type to the max radius of the feedback animation circle.
+ */
+public final class InputFeedbackRadiusMapper {
+    private final int mTinyFeedbackPixelRadius;
+    private final int mSmallFeedbackPixelRadius;
+    private final int mLargeFeedbackPixelRadius;
+
+    public InputFeedbackRadiusMapper(View view) {
+        mTinyFeedbackPixelRadius = view.getResources()
+                .getDimensionPixelSize(R.dimen.feedback_animation_radius_tiny);
+
+        mSmallFeedbackPixelRadius = view.getResources()
+                .getDimensionPixelSize(R.dimen.feedback_animation_radius_small);
+
+        mLargeFeedbackPixelRadius = view.getResources()
+                .getDimensionPixelSize(R.dimen.feedback_animation_radius_large);
+    }
+
+    /**
+     * @param feedbackToShow the feedback type to be mapped to the radius of the feedback circle.
+     * @param scaleFactor Current scale factor of the desktop canvas.
+     * @return the radius of the given feedback type. It may be 0, in which case nothing needs to
+     *         be shown.
+     */
+    public float getFeedbackRadius(DesktopView.InputFeedbackType feedbackToShow,
+                                   float scaleFactor) {
+        switch (feedbackToShow) {
+            case NONE:
+                return 0.0f;
+            case SHORT_TOUCH_ANIMATION:
+                return mSmallFeedbackPixelRadius / scaleFactor;
+            case LONG_TOUCH_ANIMATION:
+                return mLargeFeedbackPixelRadius / scaleFactor;
+            case LONG_TRACKPAD_ANIMATION:
+                // The size of the longpress trackpad animation is supposed to be close to the
+                // size of the cursor so it doesn't need to be normalized and should be scaled
+                // with the canvas.
+                return mTinyFeedbackPixelRadius;
+            default:
+                // Unreachable, but required by Google Java style and findbugs.
+                assert false : "Unreached";
+                return 0.0f;
+        }
+    }
+}