Start adding unit tests for the invariant device profile / Refactor

- removed redundant code to sort the device profiles
- removed DeviceProfileQuery class
- Added a helper method inside the test to easily generate
interpolation graph looks like:
https://docs.google.com/a/google.com/spreadsheets/d/1a1fdemrOqIDixiql77h0anWzUD3GlYfGsbP2FfIhyPM/edit?usp=sharing

Change-Id: Ia4c54a8d59a049c418c08d1b766f07ac6e1d0944

tests/src/com/android/launcher3/InvariantDeviceProfileTest.java

@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.android.launcher3;
+
+import android.graphics.PointF;
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+import android.util.Log;
+
+import com.android.launcher3.DeviceProfile;
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.util.FocusLogic;
+
+import java.util.ArrayList;
+
+/**
+ * Tests the {@link DeviceProfile} and {@link InvariantDeviceProfile}.
+ */
+@SmallTest
+public class InvariantDeviceProfileTest extends AndroidTestCase {
+
+    private static final String TAG = "DeviceProfileTest";
+    private static final boolean DEBUG = false;
+
+    private InvariantDeviceProfile mInvariantProfile;
+    private ArrayList<InvariantDeviceProfile> mPredefinedDeviceProfiles;
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        mInvariantProfile = new InvariantDeviceProfile(getContext());
+        mPredefinedDeviceProfiles = mInvariantProfile.getPredefinedDeviceProfiles();
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        // Nothing to tear down as this class only tests static methods.
+    }
+
+    public void testFindClosestDeviceProfile2() {
+        for (InvariantDeviceProfile idf: mPredefinedDeviceProfiles) {
+            ArrayList<InvariantDeviceProfile> closestProfiles =
+                    mInvariantProfile.findClosestDeviceProfiles(
+                            idf.minWidthDps, idf.minHeightDps, mPredefinedDeviceProfiles);
+            assertTrue(closestProfiles.get(0).equals(idf));
+        }
+    }
+
+    /**
+     * Used to print out how the invDistWeightedInterpolate works between device profiles to
+     * tweak the two constants that control how the interpolation curve is shaped.
+     */
+    public void testInvInterpolation() {
+
+        InvariantDeviceProfile p1 = mPredefinedDeviceProfiles.get(7); // e.g., Large Phone
+        InvariantDeviceProfile p2 = mPredefinedDeviceProfiles.get(8); // e.g., Nexus 7
+
+        ArrayList<PointF> pts = createInterpolatedPoints(
+                new PointF(p1.minWidthDps, p1.minHeightDps),
+                new PointF(p2.minWidthDps, p2.minHeightDps),
+                20f);
+
+        for (int i = 0; i < pts.size(); i++) {
+            ArrayList<InvariantDeviceProfile> closestProfiles =
+                    mInvariantProfile.findClosestDeviceProfiles(
+                            pts.get(i).x, pts.get(i).y, mPredefinedDeviceProfiles);
+            InvariantDeviceProfile result =
+                    mInvariantProfile.invDistWeightedInterpolate(
+                            pts.get(i).x, pts.get(i).y, closestProfiles);
+            if (DEBUG) {
+                Log.d(TAG, String.format("width x height = (%f, %f)] iconSize = %f",
+                        pts.get(i).x, pts.get(i).y, result.iconSize));
+            }
+        }
+    }
+
+    private ArrayList<PointF> createInterpolatedPoints(PointF a, PointF b, float numPts) {
+        ArrayList<PointF> result = new ArrayList<PointF>();
+        result.add(a);
+        for (float i = 1; i < numPts; i = i + 1.0f) {
+            result.add(new PointF((b.x * i +  a.x * (numPts - i)) / numPts,
+                    (b.y * i + a.y * (numPts - i)) / numPts));
+        }
+        result.add(b);
+        return result;
+    }
+
+    /**
+     * Ensures that system calls (e.g., WindowManager, DisplayMetrics) that require contexts are
+     * properly working to generate minimum width and height of the display.
+     */
+    public void test_hammerhead() {
+        if (!android.os.Build.DEVICE.equals("hammerhead")) {
+            return;
+        }
+        assertEquals(mInvariantProfile.numRows, 4);
+        assertEquals(mInvariantProfile.numColumns, 4);
+        assertEquals((int) mInvariantProfile.numHotseatIcons, 5);
+
+        DeviceProfile landscapeProfile = mInvariantProfile.landscapeProfile;
+        DeviceProfile portraitProfile = mInvariantProfile.portraitProfile;
+
+        assertEquals(portraitProfile.allAppsNumCols, 3);
+        assertEquals(landscapeProfile.allAppsNumCols, 5); // not used
+    }
+
+    // Add more tests for other devices, however, running them once on a single device is enough
+    // for verifying that for a platform version, the WindowManager and DisplayMetrics is
+    // working as intended.
+}