/*
* Copyright (C) 2007 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.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
public abstract class AbsSeekBar extends ProgressBar {
private Drawable mThumb;
private int mThumbOffset;
/**
* On touch, this offset plus the scaled value from the position of the
* touch will form the progress value. Usually 0.
*/
float mTouchProgressOffset;
/**
* Whether this is user seekable.
*/
boolean mIsUserSeekable = true;
/**
* On key presses (right or left), the amount to increment/decrement the
* progress.
*/
private int mKeyProgressIncrement = 1;
private static final int NO_ALPHA = 0xFF;
private float mDisabledAlpha;
public AbsSeekBar(Context context) {
super(context);
}
public AbsSeekBar(Context context, AttributeSet attrs) {
super(context, attrs);
}
public AbsSeekBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.obtainStyledAttributes(attrs,
com.android.internal.R.styleable.SeekBar, defStyle, 0);
Drawable thumb = a.getDrawable(com.android.internal.R.styleable.SeekBar_thumb);
setThumb(thumb);
int thumbOffset =
a.getDimensionPixelOffset(com.android.internal.R.styleable.SeekBar_thumbOffset, 0);
setThumbOffset(thumbOffset);
a.recycle();
a = context.obtainStyledAttributes(attrs,
com.android.internal.R.styleable.Theme, 0, 0);
mDisabledAlpha = a.getFloat(com.android.internal.R.styleable.Theme_disabledAlpha, 0.5f);
a.recycle();
}
/**
* Sets the thumb that will be drawn at the end of the progress meter within the SeekBar
*
* @param thumb Drawable representing the thumb
*/
public void setThumb(Drawable thumb) {
if (thumb != null) {
thumb.setCallback(this);
}
mThumb = thumb;
invalidate();
}
/**
* @see #setThumbOffset(int)
*/
public int getThumbOffset() {
return mThumbOffset;
}
/**
* Sets the thumb offset that allows the thumb to extend out of the range of
* the track.
*
* @param thumbOffset The offset amount in pixels.
*/
public void setThumbOffset(int thumbOffset) {
mThumbOffset = thumbOffset;
invalidate();
}
/**
* Sets the amount of progress changed via the arrow keys.
*
* @param increment The amount to increment or decrement when the user
* presses the arrow keys.
*/
public void setKeyProgressIncrement(int increment) {
mKeyProgressIncrement = increment < 0 ? -increment : increment;
}
/**
* Returns the amount of progress changed via the arrow keys.
* <p>
* By default, this will be a value that is derived from the max progress.
*
* @return The amount to increment or decrement when the user presses the
* arrow keys. This will be positive.
*/
public int getKeyProgressIncrement() {
return mKeyProgressIncrement;
}
@Override
public synchronized void setMax(int max) {
super.setMax(max);
if ((mKeyProgressIncrement == 0) || (getMax() / mKeyProgressIncrement > 20)) {
// It will take the user too long to change this via keys, change it
// to something more reasonable
setKeyProgressIncrement(Math.max(1, Math.round((float) getMax() / 20)));
}
}
@Override
protected boolean verifyDrawable(Drawable who) {
return who == mThumb || super.verifyDrawable(who);
}
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
Drawable progressDrawable = getProgressDrawable();
if (progressDrawable != null) {
progressDrawable.setAlpha(isEnabled() ? NO_ALPHA : (int) (NO_ALPHA * mDisabledAlpha));
}
if (mThumb != null && mThumb.isStateful()) {
int[] state = getDrawableState();
mThumb.setState(state);
}
}
@Override
void onProgressRefresh(float scale, boolean fromUser) {
Drawable thumb = mThumb;
if (thumb != null) {
setThumbPos(getWidth(), thumb, scale, Integer.MIN_VALUE);
/*
* Since we draw translated, the drawable's bounds that it signals
* for invalidation won't be the actual bounds we want invalidated,
* so just invalidate this whole view.
*/
invalidate();
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
Drawable d = getCurrentDrawable();
Drawable thumb = mThumb;
int thumbHeight = thumb == null ? 0 : thumb.getIntrinsicHeight();
// The max height does not incorporate padding, whereas the height
// parameter does
int trackHeight = Math.min(mMaxHeight, h - mPaddingTop - mPaddingBottom);
int max = getMax();
float scale = max > 0 ? (float) getProgress() / (float) max : 0;
if (thumbHeight > trackHeight) {
if (thumb != null) {
setThumbPos(w, thumb, scale, 0);
}
int gapForCenteringTrack = (thumbHeight - trackHeight) / 2;
if (d != null) {
// Canvas will be translated by the padding, so 0,0 is where we start drawing
d.setBounds(0, gapForCenteringTrack,
w - mPaddingRight - mPaddingLeft, h - mPaddingBottom - gapForCenteringTrack
- mPaddingTop);
}
} else {
if (d != null) {
// Canvas will be translated by the padding, so 0,0 is where we start drawing
d.setBounds(0, 0, w - mPaddingRight - mPaddingLeft, h - mPaddingBottom
- mPaddingTop);
}
int gap = (trackHeight - thumbHeight) / 2;
if (thumb != null) {
setThumbPos(w, thumb, scale, gap);
}
}
}
/**
* @param gap If set to {@link Integer#MIN_VALUE}, this will be ignored and
*/
private void setThumbPos(int w, Drawable thumb, float scale, int gap) {
int available = w - mPaddingLeft - mPaddingRight;
int thumbWidth = thumb.getIntrinsicWidth();
int thumbHeight = thumb.getIntrinsicHeight();
available -= thumbWidth;
// The extra space for the thumb to move on the track
available += mThumbOffset * 2;
int thumbPos = (int) (scale * available);
int topBound, bottomBound;
if (gap == Integer.MIN_VALUE) {
Rect oldBounds = thumb.getBounds();
topBound = oldBounds.top;
bottomBound = oldBounds.bottom;
} else {
topBound = gap;
bottomBound = gap + thumbHeight;
}
// Canvas will be translated, so 0,0 is where we start drawing
thumb.setBounds(thumbPos, topBound, thumbPos + thumbWidth, bottomBound);
}
@Override
protected synchronized void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mThumb != null) {
canvas.save();
// Translate the padding. For the x, we need to allow the thumb to
// draw in its extra space
canvas.translate(mPaddingLeft - mThumbOffset, mPaddingTop);
mThumb.draw(canvas);
canvas.restore();
}
}
@Override
protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Drawable d = getCurrentDrawable();
int thumbHeight = mThumb == null ? 0 : mThumb.getIntrinsicHeight();
int dw = 0;
int dh = 0;
if (d != null) {
dw = Math.max(mMinWidth, Math.min(mMaxWidth, d.getIntrinsicWidth()));
dh = Math.max(mMinHeight, Math.min(mMaxHeight, d.getIntrinsicHeight()));
dh = Math.max(thumbHeight, dh);
}
dw += mPaddingLeft + mPaddingRight;
dh += mPaddingTop + mPaddingBottom;
setMeasuredDimension(resolveSize(dw, widthMeasureSpec),
resolveSize(dh, heightMeasureSpec));
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (!mIsUserSeekable || !isEnabled()) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
setPressed(true);
onStartTrackingTouch();
trackTouchEvent(event);
break;
case MotionEvent.ACTION_MOVE:
trackTouchEvent(event);
attemptClaimDrag();
break;
case MotionEvent.ACTION_UP:
trackTouchEvent(event);
onStopTrackingTouch();
setPressed(false);
break;
case MotionEvent.ACTION_CANCEL:
onStopTrackingTouch();
setPressed(false);
break;
}
return true;
}
private void trackTouchEvent(MotionEvent event) {
final int width = getWidth();
final int available = width - mPaddingLeft - mPaddingRight;
int x = (int)event.getX();
float scale;
float progress = 0;
if (x < mPaddingLeft) {
scale = 0.0f;
} else if (x > width - mPaddingRight) {
scale = 1.0f;
} else {
scale = (float)(x - mPaddingLeft) / (float)available;
progress = mTouchProgressOffset;
}
final int max = getMax();
progress += scale * max;
if (progress < 0) {
progress = 0;
} else if (progress > max) {
progress = max;
}
setProgress((int) progress, true);
}
/**
* Tries to claim the user's drag motion, and requests disallowing any
* ancestors from stealing events in the drag.
*/
private void attemptClaimDrag() {
if (mParent != null) {
mParent.requestDisallowInterceptTouchEvent(true);
}
}
/**
* This is called when the user has started touching this widget.
*/
void onStartTrackingTouch() {
}
/**
* This is called when the user either releases his touch or the touch is
* canceled.
*/
void onStopTrackingTouch() {
}
/**
* Called when the user changes the seekbar's progress by using a key event.
*/
void onKeyChange() {
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
int progress = getProgress();
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_LEFT:
if (progress <= 0) break;
setProgress(progress - mKeyProgressIncrement, true);
onKeyChange();
return true;
case KeyEvent.KEYCODE_DPAD_RIGHT:
if (progress >= getMax()) break;
setProgress(progress + mKeyProgressIncrement, true);
onKeyChange();
return true;
}
return super.onKeyDown(keyCode, event);
}
}
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