/*
* Copyright (C) 2014 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.systemui.recents.views;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PixelFormat;
import android.graphics.RadialGradient;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;
import android.util.Log;
import com.android.systemui.R;
import com.android.systemui.recents.RecentsConfiguration;
/**
* A rounded rectangle drawable which also includes a shadow around. This is mostly copied from
* frameworks/support/v7/cardview/eclair-mr1/android/support/v7/widget/
* RoundRectDrawableWithShadow.java revision c42ba8c000d1e6ce85e152dfc17089a0a69e739f with a few
* modifications to suit our needs in SystemUI.
*/
class FakeShadowDrawable extends Drawable {
// used to calculate content padding
final static double COS_45 = Math.cos(Math.toRadians(45));
final static float SHADOW_MULTIPLIER = 1.5f;
final float mInsetShadow; // extra shadow to avoid gaps between card and shadow
Paint mCornerShadowPaint;
Paint mEdgeShadowPaint;
final RectF mCardBounds;
float mCornerRadius;
Path mCornerShadowPath;
// updated value with inset
float mMaxShadowSize;
// actual value set by developer
float mRawMaxShadowSize;
// multiplied value to account for shadow offset
float mShadowSize;
// actual value set by developer
float mRawShadowSize;
private boolean mDirty = true;
private final int mShadowStartColor;
private final int mShadowEndColor;
private boolean mAddPaddingForCorners = true;
/**
* If shadow size is set to a value above max shadow, we print a warning
*/
private boolean mPrintedShadowClipWarning = false;
public FakeShadowDrawable(Resources resources, RecentsConfiguration config) {
mShadowStartColor = resources.getColor(R.color.fake_shadow_start_color);
mShadowEndColor = resources.getColor(R.color.fake_shadow_end_color);
mInsetShadow = resources.getDimension(R.dimen.fake_shadow_inset);
setShadowSize(resources.getDimensionPixelSize(R.dimen.fake_shadow_size),
resources.getDimensionPixelSize(R.dimen.fake_shadow_size));
mCornerShadowPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG);
mCornerShadowPaint.setStyle(Paint.Style.FILL);
mCornerShadowPaint.setDither(true);
mCornerRadius = config.taskViewRoundedCornerRadiusPx;
mCardBounds = new RectF();
mEdgeShadowPaint = new Paint(mCornerShadowPaint);
}
@Override
public void setAlpha(int alpha) {
mCornerShadowPaint.setAlpha(alpha);
mEdgeShadowPaint.setAlpha(alpha);
}
@Override
protected void onBoundsChange(Rect bounds) {
super.onBoundsChange(bounds);
mDirty = true;
}
void setShadowSize(float shadowSize, float maxShadowSize) {
if (shadowSize < 0 || maxShadowSize < 0) {
throw new IllegalArgumentException("invalid shadow size");
}
if (shadowSize > maxShadowSize) {
shadowSize = maxShadowSize;
if (!mPrintedShadowClipWarning) {
Log.w("CardView", "Shadow size is being clipped by the max shadow size. See "
+ "{CardView#setMaxCardElevation}.");
mPrintedShadowClipWarning = true;
}
}
if (mRawShadowSize == shadowSize && mRawMaxShadowSize == maxShadowSize) {
return;
}
mRawShadowSize = shadowSize;
mRawMaxShadowSize = maxShadowSize;
mShadowSize = shadowSize * SHADOW_MULTIPLIER + mInsetShadow;
mMaxShadowSize = maxShadowSize + mInsetShadow;
mDirty = true;
invalidateSelf();
}
@Override
public boolean getPadding(Rect padding) {
int vOffset = (int) Math.ceil(calculateVerticalPadding(mRawMaxShadowSize, mCornerRadius,
mAddPaddingForCorners));
int hOffset = (int) Math.ceil(calculateHorizontalPadding(mRawMaxShadowSize, mCornerRadius,
mAddPaddingForCorners));
padding.set(hOffset, vOffset, hOffset, vOffset);
return true;
}
static float calculateVerticalPadding(float maxShadowSize, float cornerRadius,
boolean addPaddingForCorners) {
if (addPaddingForCorners) {
return (float) (maxShadowSize * SHADOW_MULTIPLIER + (1 - COS_45) * cornerRadius);
} else {
return maxShadowSize * SHADOW_MULTIPLIER;
}
}
static float calculateHorizontalPadding(float maxShadowSize, float cornerRadius,
boolean addPaddingForCorners) {
if (addPaddingForCorners) {
return (float) (maxShadowSize + (1 - COS_45) * cornerRadius);
} else {
return maxShadowSize;
}
}
@Override
public void setColorFilter(ColorFilter colorFilter) {
mCornerShadowPaint.setColorFilter(colorFilter);
mEdgeShadowPaint.setColorFilter(colorFilter);
}
@Override
public int getOpacity() {
return PixelFormat.OPAQUE;
}
@Override
public void draw(Canvas canvas) {
if (mDirty) {
buildComponents(getBounds());
mDirty = false;
}
canvas.translate(0, mRawShadowSize / 4);
drawShadow(canvas);
canvas.translate(0, -mRawShadowSize / 4);
}
private void drawShadow(Canvas canvas) {
final float edgeShadowTop = -mCornerRadius - mShadowSize;
final float inset = mCornerRadius + mInsetShadow + mRawShadowSize / 2;
final boolean drawHorizontalEdges = mCardBounds.width() - 2 * inset > 0;
final boolean drawVerticalEdges = mCardBounds.height() - 2 * inset > 0;
// LT
int saved = canvas.save();
canvas.translate(mCardBounds.left + inset, mCardBounds.top + inset);
canvas.drawPath(mCornerShadowPath, mCornerShadowPaint);
if (drawHorizontalEdges) {
canvas.drawRect(0, edgeShadowTop,
mCardBounds.width() - 2 * inset, -mCornerRadius,
mEdgeShadowPaint);
}
canvas.restoreToCount(saved);
// RB
saved = canvas.save();
canvas.translate(mCardBounds.right - inset, mCardBounds.bottom - inset);
canvas.rotate(180f);
canvas.drawPath(mCornerShadowPath, mCornerShadowPaint);
if (drawHorizontalEdges) {
canvas.drawRect(0, edgeShadowTop,
mCardBounds.width() - 2 * inset, -mCornerRadius + mShadowSize,
mEdgeShadowPaint);
}
canvas.restoreToCount(saved);
// LB
saved = canvas.save();
canvas.translate(mCardBounds.left + inset, mCardBounds.bottom - inset);
canvas.rotate(270f);
canvas.drawPath(mCornerShadowPath, mCornerShadowPaint);
if (drawVerticalEdges) {
canvas.drawRect(0, edgeShadowTop,
mCardBounds.height() - 2 * inset, -mCornerRadius, mEdgeShadowPaint);
}
canvas.restoreToCount(saved);
// RT
saved = canvas.save();
canvas.translate(mCardBounds.right - inset, mCardBounds.top + inset);
canvas.rotate(90f);
canvas.drawPath(mCornerShadowPath, mCornerShadowPaint);
if (drawVerticalEdges) {
canvas.drawRect(0, edgeShadowTop,
mCardBounds.height() - 2 * inset, -mCornerRadius, mEdgeShadowPaint);
}
canvas.restoreToCount(saved);
}
private void buildShadowCorners() {
RectF innerBounds = new RectF(-mCornerRadius, -mCornerRadius, mCornerRadius, mCornerRadius);
RectF outerBounds = new RectF(innerBounds);
outerBounds.inset(-mShadowSize, -mShadowSize);
if (mCornerShadowPath == null) {
mCornerShadowPath = new Path();
} else {
mCornerShadowPath.reset();
}
mCornerShadowPath.setFillType(Path.FillType.EVEN_ODD);
mCornerShadowPath.moveTo(-mCornerRadius, 0);
mCornerShadowPath.rLineTo(-mShadowSize, 0);
// outer arc
mCornerShadowPath.arcTo(outerBounds, 180f, 90f, false);
// inner arc
mCornerShadowPath.arcTo(innerBounds, 270f, -90f, false);
mCornerShadowPath.close();
float startRatio = mCornerRadius / (mCornerRadius + mShadowSize);
mCornerShadowPaint.setShader(new RadialGradient(0, 0, mCornerRadius + mShadowSize,
new int[]{mShadowStartColor, mShadowStartColor, mShadowEndColor},
new float[]{0f, startRatio, 1f}
, Shader.TileMode.CLAMP));
// we offset the content shadowSize/2 pixels up to make it more realistic.
// this is why edge shadow shader has some extra space
// When drawing bottom edge shadow, we use that extra space.
mEdgeShadowPaint.setShader(new LinearGradient(0, -mCornerRadius + mShadowSize, 0,
-mCornerRadius - mShadowSize,
new int[]{mShadowStartColor, mShadowStartColor, mShadowEndColor},
new float[]{0f, .5f, 1f}, Shader.TileMode.CLAMP));
}
private void buildComponents(Rect bounds) {
// Card is offset SHADOW_MULTIPLIER * maxShadowSize to account for the shadow shift.
// We could have different top-bottom offsets to avoid extra gap above but in that case
// center aligning Views inside the CardView would be problematic.
final float verticalOffset = mMaxShadowSize * SHADOW_MULTIPLIER;
mCardBounds.set(bounds.left + mMaxShadowSize, bounds.top + verticalOffset,
bounds.right - mMaxShadowSize, bounds.bottom - verticalOffset);
buildShadowCorners();
}
float getMinWidth() {
final float content = 2 *
Math.max(mRawMaxShadowSize, mCornerRadius + mInsetShadow + mRawMaxShadowSize / 2);
return content + (mRawMaxShadowSize + mInsetShadow) * 2;
}
float getMinHeight() {
final float content = 2 * Math.max(mRawMaxShadowSize, mCornerRadius + mInsetShadow
+ mRawMaxShadowSize * SHADOW_MULTIPLIER / 2);
return content + (mRawMaxShadowSize * SHADOW_MULTIPLIER + mInsetShadow) * 2;
}
}