All Apps transition with gradient and scrim.

The transition is behind a feature flag and
turned off by default.

Change-Id: I155840ba82b5a573d874376797db5f739a52d706

2 files changed, 243 insertions, 0 deletions

diff --git a/src/com/android/launcher3/graphics/RadialGradientView.java b/src/com/android/launcher3/graphics/RadialGradientView.java
new file mode 100644
index 000000000..cf6851c00
--- /dev/null
+++ b/src/com/android/launcher3/graphics/RadialGradientView.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2017 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.graphics;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.RadialGradient;
+import android.graphics.RectF;
+import android.graphics.Shader;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.animation.DecelerateInterpolator;
+
+import com.android.launcher3.R;
+import com.android.launcher3.Utilities;
+
+/**
+ * Draws a translucent radial gradient background from an initial state with progress 0.0 to a
+ * final state with progress 1.0;
+ */
+public class RadialGradientView extends View {
+
+    public static final int DEFAULT_COLOR_1 = Color.WHITE;
+    public static final int DEFAULT_COLOR_2 = Color.BLACK;
+
+    private static Bitmap sFinalGradientMask;
+    private static Bitmap sAlphaGradientMask;
+
+    // TODO needs to be cleaned up once design finalizes
+    static class Config {
+        // dimens
+        final float gradientCenterX = 0.5f;
+        final float gradientCenterY = 1.05f;
+        final float gradientHeadStartFactor = 0.35f;
+        final float gradientAlphaMaskLengthDp = 700;
+        // interpolation
+        final boolean useGradientAlphaDecel = false;
+        final float decelFactorForGradientAlpha = 2f;
+        // colors
+        final float finalGradientAlpha = 0.75f;
+        int color1 = DEFAULT_COLOR_1;
+        int color2 = DEFAULT_COLOR_2;
+    }
+
+    private final RectF mAlphaMaskRect = new RectF();
+    private final RectF mFinalMaskRect = new RectF();
+    private final Paint mPaint = new Paint();
+    private final Config mConfig = new Config();
+    private final DecelerateInterpolator mDecelInterpolator;
+    private float mProgress;
+    private int mWidth;
+    private int mHeight;
+    private final int mMaskHeight;
+    private final Context mAppContext;
+
+    public RadialGradientView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        this.mAppContext = context.getApplicationContext();
+        this.mDecelInterpolator = new DecelerateInterpolator(mConfig.decelFactorForGradientAlpha);
+        this.mMaskHeight = Utilities.pxFromDp(mConfig.gradientAlphaMaskLengthDp,
+                mAppContext.getResources().getDisplayMetrics());
+
+        if (sFinalGradientMask == null) {
+            sFinalGradientMask = Utilities.convertToAlphaMask(
+                    Utilities.createOnePixBitmap(), mConfig.finalGradientAlpha);
+        }
+        if (sAlphaGradientMask == null) {
+            Bitmap alphaMaskFromResource = BitmapFactory.decodeResource(context.getResources(),
+                    R.drawable.all_apps_alpha_mask);
+            sAlphaGradientMask = Utilities.convertToAlphaMask(
+                    alphaMaskFromResource, mConfig.finalGradientAlpha);
+        }
+    }
+
+    public void onExtractedColorsChanged(int color1, int color2) {
+        mConfig.color1 = color1;
+        mConfig.color2 = color2;
+        if (mWidth + mHeight > 0) {
+            createRadialShader();
+        }
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        this.mWidth = getMeasuredWidth();
+        this.mHeight = getMeasuredHeight();
+        if (mWidth + mHeight > 0) {
+            createRadialShader();
+        }
+    }
+
+    // only being called when colors change
+    private void createRadialShader() {
+        float radius = Math.max(mHeight, mWidth) * mConfig.gradientCenterY;
+
+        float posScreenBottom = (radius - mHeight) / radius; // center lives below screen
+        RadialGradient shader = new RadialGradient(
+                mWidth * mConfig.gradientCenterX,
+                mHeight * mConfig.gradientCenterY,
+                radius,
+                new int[] {mConfig.color1, mConfig.color1, mConfig.color2},
+                new float[] {0f, posScreenBottom, 1f},
+                Shader.TileMode.CLAMP);
+        mPaint.setShader(shader);
+    }
+
+    public void setProgress(float progress) {
+        this.mProgress = progress;
+        invalidate();
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        float head = mConfig.gradientHeadStartFactor;
+        float linearProgress = head + (mProgress * (1f - head));
+        float adjustProgress = mConfig.useGradientAlphaDecel
+                ? mDecelInterpolator.getInterpolation(linearProgress)
+                : linearProgress;
+        float startMaskY = (1f - adjustProgress) * mHeight - mMaskHeight * adjustProgress;
+
+        mAlphaMaskRect.set(0, startMaskY, mWidth, startMaskY + mMaskHeight);
+        mFinalMaskRect.set(0, startMaskY + mMaskHeight, mWidth, mHeight);
+        canvas.drawBitmap(sAlphaGradientMask, null, mAlphaMaskRect, mPaint);
+        canvas.drawBitmap(sFinalGradientMask, null, mFinalMaskRect, mPaint);
+    }
+
+}
\ No newline at end of file
diff --git a/src/com/android/launcher3/graphics/ScrimView.java b/src/com/android/launcher3/graphics/ScrimView.java
new file mode 100644
index 000000000..521fbedd6
--- /dev/null
+++ b/src/com/android/launcher3/graphics/ScrimView.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2017 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.graphics;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.RectF;
+import android.support.v4.graphics.ColorUtils;
+import android.util.AttributeSet;
+import android.view.View;
+
+import com.android.launcher3.R;
+import com.android.launcher3.Utilities;
+
+public class ScrimView extends View {
+
+    // Config
+    private static final int MASK_HEIGHT_DP = 600;
+    private static final float MASK_START_LENGTH_FACTOR = 0.4f;
+    private static final float FINAL_ALPHA = 0.87f;
+    private static final int SCRIM_COLOR = ColorUtils.setAlphaComponent(
+            Color.WHITE, (int) (FINAL_ALPHA * 255));
+
+    private static Bitmap sFinalScrimMask;
+    private static Bitmap sAlphaScrimMask;
+
+    private final int mMaskHeight;
+    private int mVisibleHeight;
+    private final int mHeadStart;
+
+    private final RectF mAlphaMaskRect = new RectF();
+    private final RectF mFinalMaskRect = new RectF();
+    private final Paint mPaint = new Paint();
+    private float mProgress;
+
+    public ScrimView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mMaskHeight = Utilities.pxFromDp(MASK_HEIGHT_DP, getResources().getDisplayMetrics());
+        mHeadStart = (int) (mMaskHeight * MASK_START_LENGTH_FACTOR);
+        mPaint.setColor(SCRIM_COLOR);
+
+        if (sFinalScrimMask == null) {
+            sFinalScrimMask = Utilities.convertToAlphaMask(
+                    Utilities.createOnePixBitmap(), FINAL_ALPHA);
+        }
+        if (sAlphaScrimMask == null) {
+            Bitmap alphaMaskFromResource = BitmapFactory.decodeResource(getResources(),
+                    R.drawable.all_apps_alpha_mask);
+            sAlphaScrimMask = Utilities.convertToAlphaMask(alphaMaskFromResource, FINAL_ALPHA);
+        }
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        int width = MeasureSpec.getSize(widthMeasureSpec);
+        mVisibleHeight = MeasureSpec.getSize(heightMeasureSpec);
+        int fullHeight = mVisibleHeight * 2 + mMaskHeight;
+        setMeasuredDimension(width, fullHeight);
+        setProgress(mProgress);
+    }
+
+    public void setProgress(float progress) {
+        mProgress = progress;
+        float initialY = mVisibleHeight - mHeadStart;
+        float fullTranslationY = mMaskHeight + initialY + mVisibleHeight;
+        float translationY = initialY - progress * fullTranslationY;
+        setTranslationY(translationY);
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        mAlphaMaskRect.set(0, 0, getWidth(), mMaskHeight);
+        mFinalMaskRect.set(0, mMaskHeight, getWidth(), getHeight());
+        canvas.drawBitmap(sAlphaScrimMask, null, mAlphaMaskRect, mPaint);
+        canvas.drawBitmap(sFinalScrimMask, null, mFinalMaskRect, mPaint);
+    }
+
+}