[Chromoting] Add InputInjector and InputInjectorWrapper for easy unittesting

remoting/android/javatests/src/org/chromium/chromoting/MockInputInjector.java

Index: remoting/android/javatests/src/org/chromium/chromoting/MockInputInjector.java
diff --git a/remoting/android/javatests/src/org/chromium/chromoting/MockInputInjector.java b/remoting/android/javatests/src/org/chromium/chromoting/MockInputInjector.java
new file mode 100644
index 0000000000000000000000000000000000000000..e3f7d42d35cbc406526c90c7eeb2ea469560aa94
--- /dev/null
+++ b/remoting/android/javatests/src/org/chromium/chromoting/MockInputInjector.java
@@ -0,0 +1,404 @@
+// 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.graphics.PointF;
+
+import junit.framework.Assert;
+
+import org.chromium.chromoting.jni.TouchEventData;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+
+/**
+ * A mock implementation of {@link InputInjector} for testing purpose.
+ */
+public final class MockInputInjector extends Assert implements InputInjector {
+    /** The base class to store an event, which represents an user activity. */
+    public abstract static class Event<T> {
+        public void assertEventEquals(T other) {
+            if (other == this) {
+                return;
+            }
+            if (other == null) {
+                assertTrue(false);

[Lambros, 2016/06/17 23:00:10]

fail() instead of assertTrue(false) ?

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+            }
+
+            assertContentMatch(other);
+        }
+
+        protected abstract void assertContentMatch(T other);
+    }
+
+    /** A mouse event. */
+    public static final class MouseEvent extends Event<MouseEvent> {
+        private final int mX;
+        private final int mY;
+        private final int mButton;
+        private final boolean mDown;
+
+        public MouseEvent(int x, int y, int button, boolean down) {
+            mX = x;
+            mY = y;
+            mButton = button;
+            mDown = down;
+        }
+
+        @Override
+        protected void assertContentMatch(MouseEvent other) {
+            assertEquals(mX, other.mX);
+            assertEquals(mY, other.mY);
+            assertEquals(mButton, other.mButton);
+            assertEquals(mDown, other.mDown);
+        }
+    }
+
+    /** A mouse wheel event. */
+    public static final class WheelEvent extends Event<WheelEvent> {
+        private final int mDeltaX;
+        private final int mDeltaY;
+
+        public WheelEvent(int deltaX, int deltaY) {
+            mDeltaX = deltaX;
+            mDeltaY = deltaY;
+        }
+
+        @Override
+        protected void assertContentMatch(WheelEvent other) {
+            assertEquals(mDeltaX, other.mDeltaX);
+            assertEquals(mDeltaY, other.mDeltaY);
+        }
+    }
+
+    /** A keyboard event. */
+    public static final class KeyEvent extends Event<KeyEvent> {
+        private final int mScanCode;
+        private final int mKeyCode;
+        private final boolean mKeyDown;
+
+        public KeyEvent(int scanCode, int keyCode, boolean keyDown) {
+            mScanCode = scanCode;
+            mKeyCode = keyCode;
+            mKeyDown = keyDown;
+        }
+
+        @Override
+        protected void assertContentMatch(KeyEvent other) {
+            assertEquals(mScanCode, other.mScanCode);
+            assertEquals(mKeyCode, other.mKeyCode);
+            assertEquals(mKeyDown, other.mKeyDown);
+        }
+    }
+
+    /** A text event. */
+    public static final class TextEvent extends Event<TextEvent> {
+        public final String mText;
+
+        public TextEvent(String text) {
+            mText = text;
+        }
+
+        @Override
+        protected void assertContentMatch(TextEvent other) {
+            if (mText == null && other.mText == null) {
+                return;
+            }
+            if (mText == null || other.mText == null) {
+                assertTrue(false);

[Lambros, 2016/06/17 23:00:10]

fail() ?

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+            }
+            assertTrue(mText.equals(other.mText));

[Lambros, 2016/06/17 23:00:10]

assertEquals() ?

[Hzj_jie, 2016/06/19 23:41:40]

Done.

+        }
+    }
+
+    /** A touch event. */
+    public static final class TouchEvent extends Event<TouchEvent> {
+        /**
+         * A random number to represent an invalid touch id for {@link assertContentMatch}.
+         * Consumers can use this number to ignore the comparasion of
+         * {@link TouchEventData#getTouchPointId()} when comparing.
+         */
+        public static final int INVALID_ID;

[Lambros, 2016/06/17 23:00:10]

I'm not sure why you would need this? Why would you ever want an
invalid ID in a TouchEvent?
Are you saying that the ID is an optional field of TouchEvent?
And how is the comparison ignored, exactly?
Are you saying if one TouchEvent has an invalid ID, it will
compare unequal to a TouchEvent with a valid ID?
Why would you need a special value for that? Wouldn't a
plain == test do the same thing?
This scheme is very unclear to me.
Looking at the implementation below, it seems that two
TouchEvents with the same INVALID_ID number would
compare not-equal with each other. Why is this useful?
This also means a TouchEvent with INVALID_ID will
compare equal with itself, but not compare equal with
a copy of itself having the exact same fields!!!

[Hzj_jie, 2016/06/19 23:41:39]

In current TouchInputStrategyTest, there is no common comparison method for each
test case. So when I was implementing this common comparison method, I needed to
take care of different comparing requirements for a TouchEvent / TouchEventData.
i.e. For some test cases, I may only care about whether a touch event has been
created at a certain place. But for some test cases -- such as tracking a move
gesture of one finger -- I may care about the TouchEventData.getTouchPointId().
So I added a TouchEventBuilder to help generate a TouchEvent. If a certain field
of one TouchEventData is interested, we can write builder.with{field name} to
set it. Otherwise a default invalid data will be added into the final
TouchEventData. And when comparing two TouchEventDatas, if one of them has the
exact invalid data, it means we are not interesting to its value, and should not
impact the final comparison result. This logic is in idMatch / positionMatch /
degreeMatch functions.

And I believe two TouchEventDatas with the exact same fields will always be the
same in current logic.

+        /**

[Lambros, 2016/06/17 23:00:10]

Blank lines above comments.

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+         * A random number to represent an invalid position for {@link #assertContentMatch}.
+         * Consumers can use this number to ignore certain float fields in an {@link TouchEventData}
+         * when comparing.
+         */
+        public static final float INVALID_POSITION;
+        /**
+         * A number to represent an invalid angle in radians for {@link #assertContentMatch}.
+         * Consumers can use this number to ignore the comparasion of
+         * {@link TouchEventData#getTouchPointAngle} when comparing.
+         */
+        public static final float INVALID_RADIANS;
+        private final TouchEventData.EventType mEventType;
+        private final TouchEventData[] mData;
+
+        static {
+            INVALID_ID = -883;

[Lambros, 2016/06/17 23:00:10]

Do we want a static block for this? I think we usually
initialize constants at the declaration.

[Hzj_jie, 2016/06/19 23:41:40]

Done.

+            INVALID_POSITION = -763.273f;
+            INVALID_RADIANS = 3 * (float) Math.PI;
+        }
+
+        public TouchEvent(TouchEventData.EventType eventType,
+                          TouchEventData[] data) {
+            mEventType = eventType;
+            mData = (data == null ? null : Arrays.copyOf(data, data.length));
+        }
+
+        private static boolean idMatch(int left, int right) {
+            return left == right
+                   || left == INVALID_ID

[Lambros, 2016/06/17 23:00:10]

Wrong indentation. git cl format

[Hzj_jie, 2016/06/19 23:41:40]

Done.

+                   || right == INVALID_ID;
+        }
+
+        private static boolean positionMatch(float left, float right) {
+            return left == right
+                   || left == INVALID_POSITION
+                   || right == INVALID_POSITION;
+        }
+
+        private static boolean degreeMatch(float left, float right) {
+            // 3PI = 540

[Lambros, 2016/06/17 23:00:10]

Can you clarify this comment? Or just remove it?

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+            return left == right

[Lambros, 2016/06/17 23:00:10]

This exact compare of floats will probably trigger a FindBugs warning.

If you are doing any arithmetic of floats that might be inexact, you
should fix this test to allow for a small error.

Otherwise, just suppress the warning if you see one.

[Hzj_jie, 2016/06/19 23:41:39]

Indeed the floats should be exact equals, there should be no small errors. Since
all the numbers are coming from test cases. We do not have any random generated
floats.

+                   || left > 360

[Lambros, 2016/06/17 23:00:10]

This is very weird.
Firstly: Why not define INVALID_DEGREES like you have done with INVALID_RADIANS?
Secondly: For example, if |left| is 123 and |right| is 999, this test will
report that they match! Is that what you intended?

[Hzj_jie, 2016/06/19 23:41:39]

Good point.

+                   || right > 360;
+        }
+
+        private static void assertContentMatch(TouchEventData left, TouchEventData right) {
+            assertTrue(idMatch(left.getTouchPointId(), right.getTouchPointId()));
+            assertTrue(positionMatch(left.getTouchPointX(), right.getTouchPointX()));
+            assertTrue(positionMatch(left.getTouchPointY(), right.getTouchPointY()));
+            assertTrue(positionMatch(left.getTouchPointRadiusX(), right.getTouchPointRadiusX()));
+            assertTrue(positionMatch(left.getTouchPointRadiusY(), right.getTouchPointRadiusY()));
+            assertTrue(degreeMatch(left.getTouchPointAngle(), right.getTouchPointAngle()));
+            assertTrue(positionMatch(left.getTouchPointPressure(), right.getTouchPointPressure()));
+        }
+
+        private static void assertDataEquals(TouchEventData left, TouchEventData right) {
+            if (left == null && right == null) {
+                return;
+            }
+            if (left == null || right == null) {
+                assertTrue(false);
+            }
+            assertContentMatch(left, right);
+        }
+
+        private int dataSize() {
+            return mData == null ? 0 : mData.length;
+        }
+
+        @Override
+        protected void assertContentMatch(TouchEvent other) {
+            assertEquals(mEventType, other.mEventType);
+            if (dataSize() != 0 && other.dataSize() != 0) {

[Lambros, 2016/06/17 23:00:10]

This is incorrect: && should probably be ||
If exactly one of these is 0:
The && will be false and the body will not execute, so this
function will no-op, behaving as if the contents matched, which is
not correct.

You could maybe remove the 'if' completely. For the (0,0)
case, the for-loop will be a no-op.

[Hzj_jie, 2016/06/19 23:41:39]

I may explain more about this in the comments. This is by-design to cover
TouchInputStrategyTest.assertTouchEventInjected function. i.e. A test case may
only care about whether a TouchEvent with a certain TouchEventData.EventType has
been injected, but does not really care about the detail TouchEventData.
Considering sendTouchEvent with an empty TouchEventData array is totally wrong,
an empty TouchEventData array in TouchEvent is also an indicator to ignore this
field. I have added an assertion in sendTouchEvent to make sure no production
logic could eventually do this kind of thing. I have also added similar logic
for each INVALID_{field} above.

+                assertEquals(dataSize(), other.dataSize());
+                for (int i = 0; i < dataSize(); i++) {
+                    assertDataEquals(mData[i], other.mData[i]);
+                }
+            }
+        }
+
+    }
+
+    private final LinkedList<MouseEvent> mMouseEvents;
+    private final LinkedList<WheelEvent> mWheelEvents;
+    private final LinkedList<KeyEvent> mKeyEvents;
+    private final LinkedList<TextEvent> mTextEvents;
+    private final LinkedList<TouchEvent> mTouchEvents;
+
+    public MockInputInjector() {
+        mMouseEvents = new LinkedList<>();
+        mWheelEvents = new LinkedList<>();
+        mKeyEvents = new LinkedList<>();
+        mTextEvents = new LinkedList<>();
+        mTouchEvents = new LinkedList<>();
+    }
+
+    /**
+     * Compares the first |right|.length events with the ones in |left|, asserts they are equal, and
+     * consumes these events from both |left| and |right|.
+     */
+    private static <E extends Event<E>> void assertContains(LinkedList<E> left,
+                                                            LinkedList<E> right) {
+        if (left == null && right == null) {
+            return;
+        }
+        if (left == null || right == null) {
+            assertTrue(false);
+            return;
+        }
+        assertTrue(left.size() >= right.size());
+        while (right.size() > 0) {
+            E leftEvent = left.removeFirst();
+            E rightEvent = right.removeFirst();
+            if (leftEvent == null) {
+                assertNull(rightEvent);
+            } else {
+                leftEvent.assertEventEquals(rightEvent);
+            }
+        }
+    }
+
+    public void clear() {
+        mMouseEvents.clear();
+        mWheelEvents.clear();
+        mKeyEvents.clear();
+        mTextEvents.clear();
+        mTouchEvents.clear();
+    }
+
+    /**
+     * Compares the first |other|.length events with {@link #mMouseEvents} in this instance,
+     * asserts they are equal, and consumes these events in both this instance and |other|.
+     */
+    public void assertContainsMouseEvents(LinkedList<MouseEvent> other) {

[Lambros, 2016/06/17 23:00:10]

Does this need to consume |other|?
Does this need to be a LinkedList?
Maybe you could simplify the call-sites by allowing
|other| to be any iterable list of MouseEvent (ideally, an
array could be passed in directly)?

[Hzj_jie, 2016/06/19 23:41:40]

Done.

+        assertContains(mMouseEvents, other);
+    }
+
+    /**
+     * Compares the first |other|.length events with {@link #mTouchEvents} in this instance,
+     * asserts they are equal, and consumes these events in both this instance and |other|.
+     */
+    public void assertContainsTouchEvents(LinkedList<TouchEvent> other) {
+        assertContains(mTouchEvents, other);
+    }
+
+    /** Asserts current instance is emtpy. */

[Lambros, 2016/06/17 23:00:10]

empty

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+    public void assertEmpty() {
+        assertTrue(mMouseEvents.isEmpty());
+        assertTrue(mWheelEvents.isEmpty());
+        assertTrue(mKeyEvents.isEmpty());
+        assertTrue(mTextEvents.isEmpty());
+        assertTrue(mTouchEvents.isEmpty());
+    }
+
+    /**
+     * Checks whether the first two events in {@link #mTouchEvents} are representing a down and
+     * an up action at specified position |x|, |y|, and consumes these events.
+     */
+    public void assertTapInjected(float x, float y) {
+        assertTouchEventInjected(TouchEventData.EventType.TOUCH_EVENT_START, x, y);
+        assertTouchEventInjected(TouchEventData.EventType.TOUCH_EVENT_END, x, y);
+    }
+
+    /**
+     * Checks whether the first event in {@link #mTouchEvents} is representing an event with type
+     * |eventType| and at specified position |x|, |y|, and consumes this event.
+     */
+    public void assertTouchEventInjected(TouchEventData.EventType eventType, float x, float y) {
+        assertContainsTouchEvents(new LinkedList<TouchEvent>(Arrays.asList(new TouchEvent[] {
+                (new TouchEventBuilder())
+                          .withEventType(eventType)
+                          .withX(x)
+                          .withY(y)
+                          .append()
+                          .build(),
+        })));
+    }
+
+    /**
+     * Checks whether the first event in {@link #mTouchEvents} is representing an event with type
+     * |eventType|, and consumes this event.
+     */
+    public void assertTouchEventInjected(TouchEventData.EventType eventType) {
+        assertContainsTouchEvents(new LinkedList<TouchEvent>(Arrays.asList(new TouchEvent[] {
+                (new TouchEventBuilder()).withEventType(eventType).build(),
+        })));
+    }
+
+    /**
+     * Checks whether the first two events in {@link #mMouseEvents} are representing a down and an
+     * up action with |button| at specified position |x|, |y|, and consumes these events.
+     */
+    public void assertClickInjected(int button, int x, int y) {
+        assertContainsMouseEvents(new LinkedList<MouseEvent>(Arrays.asList(new MouseEvent[] {
+                new MouseEvent(x, y, button, true),
+                new MouseEvent(x, y, button, false),
+        })));
+    }
+
+    public void assertTouchMoveEventInjected(PointF[] initPositions,
+                                             int stepX,
+                                             int stepY,
+                                             int moveCount) {
+        LinkedList<TouchEvent> events = new LinkedList<>();
+        assertTrue(initPositions != null && initPositions.length > 0);
+        for (int i = 0; i < initPositions.length; i++) {
+            assertNotNull(initPositions[i]);
+            events.add((new TouchEventBuilder())

[Lambros, 2016/06/17 23:00:10]

I don't think you need parentheses around new TouchEventBuilder() ?

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+                    .withEventType(TouchEventData.EventType.TOUCH_EVENT_START)
+                    .withX(initPositions[i].x)
+                    .withY(initPositions[i].y)
+                    .append()
+                    .build());
+        }
+        // These tests send a single event for each finger that is moved.  E.G. If we are injecting

[Lambros, 2016/06/17 23:00:10]

Blank line.

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+        // a pan event with two fingers, then every two TouchEvents represents one 'frame' of the
+        // motion sequence.  Here we determine which iteration this event represents so we can use
+        // that to accurately compare the locations with the expected values.
+        for (int i = 0; i < moveCount; i++) {
+            for (int j = 0; j < initPositions.length; j++) {
+                TouchEventBuilder builder = new TouchEventBuilder();
+                builder.withEventType(TouchEventData.EventType.TOUCH_EVENT_MOVE);
+                for (int k = 0; k < initPositions.length; k++) {
+                    // We inject one finger at a time which means that finger will have the correct
+                    // value but other fingers may still be stepSize behind it.
+                    int currentStep = i - 1;
+                    if (j >= k) {
+                        currentStep++;
+                    }
+                    if (currentStep < 0) {
+                        currentStep = 0;
+                    }
+                    builder.withX(initPositions[k].x + currentStep * stepX)
+                           .withY(initPositions[k].y + currentStep * stepY)
+                           .append();
+                }
+                events.add(builder.build());
+            }
+        }
+
+        assertContainsTouchEvents(events);
+    }
+
+    /**
+     * Checks whether the first two events in {@link #mMouseEvents} are representing a down and an
+     * up action with right button at specified position |x|, |y|, and consumes these events.
+     */
+    public void assertRightClickInjected(int x, int y) {
+        assertClickInjected(TouchInputHandler.BUTTON_RIGHT, x, y);
+    }
+
+    // ---------------- Implementations of InputInjector ----------------------
+    @Override
+    public void sendMouseEvent(int x, int y, int whichButton, boolean buttonDown) {
+        mMouseEvents.add(new MouseEvent(x, y, whichButton, buttonDown));
+    }
+
+    @Override
+    public void sendMouseWheelEvent(int deltaX, int deltaY) {
+        mWheelEvents.add(new WheelEvent(deltaX, deltaY));
+    }
+
+    @Override
+    public boolean sendKeyEvent(int scanCode, int keyCode, boolean keyDown) {
+        mKeyEvents.add(new KeyEvent(scanCode, keyCode, keyDown));
+        // Note: This implementation is not consistent with jni.Client, which may return false when

[Lambros, 2016/06/17 23:00:10]

Blank line.

[Hzj_jie, 2016/06/19 23:41:39]

Done.

+        // scanCode and keyCode cannot be mapped to a usb key code.
+        return true;
+    }
+
+    @Override
+    public void sendTextEvent(String text) {
+        mTextEvents.add(new TextEvent(text));
+    }
+
+    @Override
+    public void sendTouchEvent(TouchEventData.EventType eventType, TouchEventData[] data) {
+        mTouchEvents.add(new TouchEvent(eventType, data));
+    }
+}