/*
* Copyright (C) 2006 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 android.widget;
import android.annotation.NonNull;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import com.android.internal.widget.ScrollBarUtils;
/**
* This is only used by View for displaying its scroll bars. It should probably
* be moved in to the view package since it is used in that lower-level layer.
* For now, we'll hide it so it can be cleaned up later.
*
* {@hide}
*/
public class ScrollBarDrawable extends Drawable implements Drawable.Callback {
private Drawable mVerticalTrack;
private Drawable mHorizontalTrack;
private Drawable mVerticalThumb;
private Drawable mHorizontalThumb;
private int mRange;
private int mOffset;
private int mExtent;
private boolean mVertical;
private boolean mBoundsChanged;
private boolean mRangeChanged;
private boolean mAlwaysDrawHorizontalTrack;
private boolean mAlwaysDrawVerticalTrack;
private boolean mMutated;
private int mAlpha = 255;
private boolean mHasSetAlpha;
private ColorFilter mColorFilter;
private boolean mHasSetColorFilter;
/**
* Indicate whether the horizontal scrollbar track should always be drawn
* regardless of the extent. Defaults to false.
*
* @param alwaysDrawTrack Whether the track should always be drawn
*
* @see #getAlwaysDrawHorizontalTrack()
*/
public void setAlwaysDrawHorizontalTrack(boolean alwaysDrawTrack) {
mAlwaysDrawHorizontalTrack = alwaysDrawTrack;
}
/**
* Indicate whether the vertical scrollbar track should always be drawn
* regardless of the extent. Defaults to false.
*
* @param alwaysDrawTrack Whether the track should always be drawn
*
* @see #getAlwaysDrawVerticalTrack()
*/
public void setAlwaysDrawVerticalTrack(boolean alwaysDrawTrack) {
mAlwaysDrawVerticalTrack = alwaysDrawTrack;
}
/**
* @return whether the vertical scrollbar track should always be drawn
* regardless of the extent.
*
* @see #setAlwaysDrawVerticalTrack(boolean)
*/
public boolean getAlwaysDrawVerticalTrack() {
return mAlwaysDrawVerticalTrack;
}
/**
* @return whether the horizontal scrollbar track should always be drawn
* regardless of the extent.
*
* @see #setAlwaysDrawHorizontalTrack(boolean)
*/
public boolean getAlwaysDrawHorizontalTrack() {
return mAlwaysDrawHorizontalTrack;
}
public void setParameters(int range, int offset, int extent, boolean vertical) {
if (mVertical != vertical) {
mVertical = vertical;
mBoundsChanged = true;
}
if (mRange != range || mOffset != offset || mExtent != extent) {
mRange = range;
mOffset = offset;
mExtent = extent;
mRangeChanged = true;
}
}
@Override
public void draw(Canvas canvas) {
final boolean vertical = mVertical;
final int extent = mExtent;
final int range = mRange;
boolean drawTrack = true;
boolean drawThumb = true;
if (extent <= 0 || range <= extent) {
drawTrack = vertical ? mAlwaysDrawVerticalTrack : mAlwaysDrawHorizontalTrack;
drawThumb = false;
}
final Rect r = getBounds();
if (canvas.quickReject(r.left, r.top, r.right, r.bottom, Canvas.EdgeType.AA)) {
return;
}
if (drawTrack) {
drawTrack(canvas, r, vertical);
}
if (drawThumb) {
final int scrollBarLength = vertical ? r.height() : r.width();
final int thickness = vertical ? r.width() : r.height();
final int thumbLength =
ScrollBarUtils.getThumbLength(scrollBarLength, thickness, extent, range);
final int thumbOffset =
ScrollBarUtils.getThumbOffset(scrollBarLength, thumbLength, extent, range,
mOffset);
drawThumb(canvas, r, thumbOffset, thumbLength, vertical);
}
}
@Override
protected void onBoundsChange(Rect bounds) {
super.onBoundsChange(bounds);
mBoundsChanged = true;
}
@Override
public boolean isStateful() {
return (mVerticalTrack != null && mVerticalTrack.isStateful())
|| (mVerticalThumb != null && mVerticalThumb.isStateful())
|| (mHorizontalTrack != null && mHorizontalTrack.isStateful())
|| (mHorizontalThumb != null && mHorizontalThumb.isStateful())
|| super.isStateful();
}
@Override
protected boolean onStateChange(int[] state) {
boolean changed = super.onStateChange(state);
if (mVerticalTrack != null) {
changed |= mVerticalTrack.setState(state);
}
if (mVerticalThumb != null) {
changed |= mVerticalThumb.setState(state);
}
if (mHorizontalTrack != null) {
changed |= mHorizontalTrack.setState(state);
}
if (mHorizontalThumb != null) {
changed |= mHorizontalThumb.setState(state);
}
return changed;
}
private void drawTrack(Canvas canvas, Rect bounds, boolean vertical) {
final Drawable track;
if (vertical) {
track = mVerticalTrack;
} else {
track = mHorizontalTrack;
}
if (track != null) {
if (mBoundsChanged) {
track.setBounds(bounds);
}
track.draw(canvas);
}
}
private void drawThumb(Canvas canvas, Rect bounds, int offset, int length, boolean vertical) {
final boolean changed = mRangeChanged || mBoundsChanged;
if (vertical) {
if (mVerticalThumb != null) {
final Drawable thumb = mVerticalThumb;
if (changed) {
thumb.setBounds(bounds.left, bounds.top + offset,
bounds.right, bounds.top + offset + length);
}
thumb.draw(canvas);
}
} else {
if (mHorizontalThumb != null) {
final Drawable thumb = mHorizontalThumb;
if (changed) {
thumb.setBounds(bounds.left + offset, bounds.top,
bounds.left + offset + length, bounds.bottom);
}
thumb.draw(canvas);
}
}
}
public void setVerticalThumbDrawable(Drawable thumb) {
if (mVerticalThumb != null) {
mVerticalThumb.setCallback(null);
}
propagateCurrentState(thumb);
mVerticalThumb = thumb;
}
public void setVerticalTrackDrawable(Drawable track) {
if (mVerticalTrack != null) {
mVerticalTrack.setCallback(null);
}
propagateCurrentState(track);
mVerticalTrack = track;
}
public void setHorizontalThumbDrawable(Drawable thumb) {
if (mHorizontalThumb != null) {
mHorizontalThumb.setCallback(null);
}
propagateCurrentState(thumb);
mHorizontalThumb = thumb;
}
public void setHorizontalTrackDrawable(Drawable track) {
if (mHorizontalTrack != null) {
mHorizontalTrack.setCallback(null);
}
propagateCurrentState(track);
mHorizontalTrack = track;
}
private void propagateCurrentState(Drawable d) {
if (d != null) {
if (mMutated) {
d.mutate();
}
d.setState(getState());
d.setCallback(this);
if (mHasSetAlpha) {
d.setAlpha(mAlpha);
}
if (mHasSetColorFilter) {
d.setColorFilter(mColorFilter);
}
}
}
public int getSize(boolean vertical) {
if (vertical) {
return mVerticalTrack != null ? mVerticalTrack.getIntrinsicWidth() :
mVerticalThumb != null ? mVerticalThumb.getIntrinsicWidth() : 0;
} else {
return mHorizontalTrack != null ? mHorizontalTrack.getIntrinsicHeight() :
mHorizontalThumb != null ? mHorizontalThumb.getIntrinsicHeight() : 0;
}
}
@Override
public ScrollBarDrawable mutate() {
if (!mMutated && super.mutate() == this) {
if (mVerticalTrack != null) {
mVerticalTrack.mutate();
}
if (mVerticalThumb != null) {
mVerticalThumb.mutate();
}
if (mHorizontalTrack != null) {
mHorizontalTrack.mutate();
}
if (mHorizontalThumb != null) {
mHorizontalThumb.mutate();
}
mMutated = true;
}
return this;
}
@Override
public void setAlpha(int alpha) {
mAlpha = alpha;
mHasSetAlpha = true;
if (mVerticalTrack != null) {
mVerticalTrack.setAlpha(alpha);
}
if (mVerticalThumb != null) {
mVerticalThumb.setAlpha(alpha);
}
if (mHorizontalTrack != null) {
mHorizontalTrack.setAlpha(alpha);
}
if (mHorizontalThumb != null) {
mHorizontalThumb.setAlpha(alpha);
}
}
@Override
public int getAlpha() {
return mAlpha;
}
@Override
public void setColorFilter(ColorFilter colorFilter) {
mColorFilter = colorFilter;
mHasSetColorFilter = true;
if (mVerticalTrack != null) {
mVerticalTrack.setColorFilter(colorFilter);
}
if (mVerticalThumb != null) {
mVerticalThumb.setColorFilter(colorFilter);
}
if (mHorizontalTrack != null) {
mHorizontalTrack.setColorFilter(colorFilter);
}
if (mHorizontalThumb != null) {
mHorizontalThumb.setColorFilter(colorFilter);
}
}
@Override
public ColorFilter getColorFilter() {
return mColorFilter;
}
@Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
@Override
public void invalidateDrawable(@NonNull Drawable who) {
invalidateSelf();
}
@Override
public void scheduleDrawable(@NonNull Drawable who, @NonNull Runnable what, long when) {
scheduleSelf(what, when);
}
@Override
public void unscheduleDrawable(@NonNull Drawable who, @NonNull Runnable what) {
unscheduleSelf(what);
}
@Override
public String toString() {
return "ScrollBarDrawable: range=" + mRange + " offset=" + mOffset +
" extent=" + mExtent + (mVertical ? " V" : " H");
}
}