/*
* Copyright (C) 2010 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.dwdesign.tweetings.view;
import com.dwdesign.tweetings.R;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.ViewConfiguration;
import android.widget.CompoundButton;
/**
* A Switch is a two-state toggle switch widget that can select between two
* options. The user may drag the "thumb" back and forth to choose the selected
* option, or simply tap to toggle as if it were a checkbox. The
* {@link #setText(CharSequence) text} property controls the text displayed in
* the label for the switch, whereas the {@link #setTextOff(CharSequence) off}
* and {@link #setTextOn(CharSequence) on} text controls the text on the thumb.
* Similarly, the {@link #setTextAppearance(android.content.Context, int)
* textAppearance} and the related setTypeface() methods control the typeface
* and style of label text, whereas the
* {@link #setSwitchTextAppearance(android.content.Context, int)
* switchTextAppearance} and the related seSwitchTypeface() methods control that
* of the thumb.
*
*/
public class Switch extends CompoundButton {
private static final int TOUCH_MODE_IDLE = 0;
private static final int TOUCH_MODE_DOWN = 1;
private static final int TOUCH_MODE_DRAGGING = 2;
private final Drawable mThumbDrawable;
private final Drawable mTrackDrawable;
private final int mThumbTextPadding;
private final int mSwitchMinWidth;
private final int mSwitchPadding;
private CharSequence mTextOn;
private CharSequence mTextOff;
private int mTouchMode;
private final int mTouchSlop;
private float mTouchX;
private float mTouchY;
private final VelocityTracker mVelocityTracker = VelocityTracker.obtain();
private final int mMinFlingVelocity;
private float mThumbPosition;
private int mSwitchWidth;
private int mSwitchHeight;
private int mThumbWidth; // Does not include padding
private int mSwitchLeft;
private int mSwitchTop;
private int mSwitchRight;
private int mSwitchBottom;
private final TextPaint mTextPaint;
private ColorStateList mTextColors;
private Layout mOnLayout;
private Layout mOffLayout;
private final Rect mTempRect = new Rect();
private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };
/**
* Construct a new Switch with default styling.
*
* @param context The Context that will determine this widget's theming.
*/
public Switch(final Context context) {
this(context, null);
}
/**
* Construct a new Switch with default styling, overriding specific style
* attributes as requested.
*
* @param context The Context that will determine this widget's theming.
* @param attrs Specification of attributes that should deviate from default
* styling.
*/
public Switch(final Context context, final AttributeSet attrs) {
this(context, attrs, R.attr.switchStyle);
}
/**
* Construct a new Switch with a default style determined by the given theme
* attribute, overriding specific style attributes as requested.
*
* @param context The Context that will determine this widget's theming.
* @param attrs Specification of attributes that should deviate from the
* default styling.
* @param defStyle An attribute ID within the active theme containing a
* reference to the default style for this widget. e.g.
* android.R.attr.switchStyle.
*/
public Switch(final Context context, final AttributeSet attrs, final int defStyle) {
super(context, attrs, defStyle);
mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Switch, defStyle, 0);
mThumbDrawable = a.getDrawable(R.styleable.Switch_thumb);
mTrackDrawable = a.getDrawable(R.styleable.Switch_track);
mTextOn = a.getText(R.styleable.Switch_textOn);
mTextOff = a.getText(R.styleable.Switch_textOff);
mThumbTextPadding = a.getDimensionPixelSize(R.styleable.Switch_thumbTextPadding, 0);
mSwitchMinWidth = a.getDimensionPixelSize(R.styleable.Switch_switchMinWidth, 0);
mSwitchPadding = a.getDimensionPixelSize(R.styleable.Switch_switchPadding, 0);
final int appearance = a.getResourceId(R.styleable.Switch_switchTextAppearance, 0);
if (appearance != 0) {
setSwitchTextAppearance(context, appearance);
}
a.recycle();
final ViewConfiguration config = ViewConfiguration.get(context);
mTouchSlop = config.getScaledTouchSlop();
mMinFlingVelocity = config.getScaledMinimumFlingVelocity();
// Refresh display with current params
refreshDrawableState();
setChecked(isChecked());
}
@Override
public int getCompoundPaddingRight() {
int padding = super.getCompoundPaddingRight() + mSwitchWidth;
if (!TextUtils.isEmpty(getText())) {
padding += mSwitchPadding;
}
return padding;
}
/**
* Returns the text displayed when the button is not in the checked state.
*/
public CharSequence getTextOff() {
return mTextOff;
}
/**
* Returns the text displayed when the button is in the checked state.
*/
public CharSequence getTextOn() {
return mTextOn;
}
@Override
public void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec) {
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
if (mOnLayout == null) {
mOnLayout = makeLayout(mTextOn);
}
if (mOffLayout == null) {
mOffLayout = makeLayout(mTextOff);
}
mTrackDrawable.getPadding(mTempRect);
final int maxTextWidth = Math.max(mOnLayout.getWidth(), mOffLayout.getWidth());
final int switchWidth = Math.max(mSwitchMinWidth, maxTextWidth * 2 + mThumbTextPadding * 4 + mTempRect.left
+ mTempRect.right);
final int switchHeight = mTrackDrawable.getIntrinsicHeight();
mThumbWidth = maxTextWidth + mThumbTextPadding * 2;
switch (widthMode) {
case MeasureSpec.AT_MOST:
widthSize = Math.min(widthSize, switchWidth);
break;
case MeasureSpec.UNSPECIFIED:
widthSize = switchWidth;
break;
case MeasureSpec.EXACTLY:
// Just use what we were given
break;
}
switch (heightMode) {
case MeasureSpec.AT_MOST:
heightSize = Math.min(heightSize, switchHeight);
break;
case MeasureSpec.UNSPECIFIED:
heightSize = switchHeight;
break;
case MeasureSpec.EXACTLY:
// Just use what we were given
break;
}
mSwitchWidth = switchWidth;
mSwitchHeight = switchHeight;
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final int measuredHeight = getMeasuredHeight();
if (measuredHeight < switchHeight) {
setMeasuredDimension(getMeasuredWidth(), switchHeight);
}
}
@Override
public boolean onTouchEvent(final MotionEvent ev) {
mVelocityTracker.addMovement(ev);
final int action = ev.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
if (isEnabled() && hitThumb(x, y)) {
mTouchMode = TOUCH_MODE_DOWN;
mTouchX = x;
mTouchY = y;
}
break;
}
case MotionEvent.ACTION_MOVE: {
switch (mTouchMode) {
case TOUCH_MODE_IDLE:
// Didn't target the thumb, treat normally.
break;
case TOUCH_MODE_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
if (Math.abs(x - mTouchX) > mTouchSlop || Math.abs(y - mTouchY) > mTouchSlop) {
mTouchMode = TOUCH_MODE_DRAGGING;
getParent().requestDisallowInterceptTouchEvent(true);
mTouchX = x;
mTouchY = y;
return true;
}
break;
}
case TOUCH_MODE_DRAGGING: {
final float x = ev.getX();
final float dx = x - mTouchX;
final float newPos = Math.max(0, Math.min(mThumbPosition + dx, getThumbScrollRange()));
if (newPos != mThumbPosition) {
mThumbPosition = newPos;
mTouchX = x;
invalidate();
}
return true;
}
}
break;
}
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL: {
if (mTouchMode == TOUCH_MODE_DRAGGING) {
stopDrag(ev);
return true;
}
mTouchMode = TOUCH_MODE_IDLE;
mVelocityTracker.clear();
break;
}
}
return super.onTouchEvent(ev);
}
@Override
public void setChecked(final boolean checked) {
super.setChecked(checked);
mThumbPosition = checked ? getThumbScrollRange() : 0;
invalidate();
}
/**
* Sets the switch text color, size, style, hint color, and highlight color
* from the specified TextAppearance resource.
*/
public void setSwitchTextAppearance(final Context context, final int resid) {
final TypedArray appearance = context.obtainStyledAttributes(resid, R.styleable.TextAppearance);
ColorStateList colors;
int ts;
colors = appearance.getColorStateList(R.styleable.TextAppearance_textColor);
if (colors != null) {
mTextColors = colors;
} else {
// If no color set in TextAppearance, default to the view's
// textColor
mTextColors = getTextColors();
}
ts = appearance.getDimensionPixelSize(R.styleable.TextAppearance_textSize, 0);
if (ts != 0) {
if (ts != mTextPaint.getTextSize()) {
mTextPaint.setTextSize(ts);
requestLayout();
}
}
appearance.recycle();
}
/**
* Sets the typeface in which the text should be displayed on the switch.
* Note that not all Typeface families actually have bold and italic
* variants, so you may need to use
* {@link #setSwitchTypeface(Typeface, int)} to get the appearance that you
* actually want.
*
* @attr ref android.R.styleable#TextView_typeface
* @attr ref android.R.styleable#TextView_textStyle
*/
public void setSwitchTypeface(final Typeface tf) {
if (mTextPaint.getTypeface() != tf) {
mTextPaint.setTypeface(tf);
requestLayout();
invalidate();
}
}
/**
* Sets the typeface and style in which the text should be displayed on the
* switch, and turns on the fake bold and italic bits in the Paint if the
* Typeface that you provided does not have all the bits in the style that
* you specified.
*/
public void setSwitchTypeface(Typeface tf, final int style) {
if (style > 0) {
if (tf == null) {
tf = Typeface.defaultFromStyle(style);
} else {
tf = Typeface.create(tf, style);
}
setSwitchTypeface(tf);
// now compute what (if any) algorithmic styling is needed
final int typefaceStyle = tf != null ? tf.getStyle() : 0;
final int need = style & ~typefaceStyle;
mTextPaint.setFakeBoldText((need & Typeface.BOLD) != 0);
mTextPaint.setTextSkewX((need & Typeface.ITALIC) != 0 ? -0.25f : 0);
} else {
mTextPaint.setFakeBoldText(false);
mTextPaint.setTextSkewX(0);
setSwitchTypeface(tf);
}
}
/**
* Sets the text displayed when the button is not in the checked state.
*/
public void setTextOff(final CharSequence textOff) {
mTextOff = textOff;
requestLayout();
}
/**
* Sets the text displayed when the button is in the checked state.
*/
public void setTextOn(final CharSequence textOn) {
mTextOn = textOn;
requestLayout();
}
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
final int[] myDrawableState = getDrawableState();
// Set the state of the Drawable
// Drawable may be null when checked state is set from XML, from super
// constructor
if (mThumbDrawable != null) {
mThumbDrawable.setState(myDrawableState);
}
if (mTrackDrawable != null) {
mTrackDrawable.setState(myDrawableState);
}
invalidate();
}
@Override
protected int[] onCreateDrawableState(final int extraSpace) {
final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
if (isChecked()) {
mergeDrawableStates(drawableState, CHECKED_STATE_SET);
}
return drawableState;
}
@Override
protected void onDraw(final Canvas canvas) {
super.onDraw(canvas);
// Draw the switch
final int switchLeft = mSwitchLeft;
final int switchTop = mSwitchTop;
final int switchRight = mSwitchRight;
final int switchBottom = mSwitchBottom;
mTrackDrawable.setBounds(switchLeft, switchTop, switchRight, switchBottom);
mTrackDrawable.draw(canvas);
canvas.save();
mTrackDrawable.getPadding(mTempRect);
final int switchInnerLeft = switchLeft + mTempRect.left;
final int switchInnerTop = switchTop + mTempRect.top;
final int switchInnerRight = switchRight - mTempRect.right;
final int switchInnerBottom = switchBottom - mTempRect.bottom;
canvas.clipRect(switchInnerLeft, switchTop, switchInnerRight, switchBottom);
mThumbDrawable.getPadding(mTempRect);
final int thumbPos = (int) (mThumbPosition + 0.5f);
final int thumbLeft = switchInnerLeft - mTempRect.left + thumbPos;
final int thumbRight = switchInnerLeft + thumbPos + mThumbWidth + mTempRect.right;
mThumbDrawable.setBounds(thumbLeft, switchTop, thumbRight, switchBottom);
mThumbDrawable.draw(canvas);
// mTextColors should not be null, but just in case
if (mTextColors != null) {
mTextPaint.setColor(mTextColors.getColorForState(getDrawableState(), mTextColors.getDefaultColor()));
}
mTextPaint.drawableState = getDrawableState();
final Layout switchText = getTargetCheckedState() ? mOnLayout : mOffLayout;
canvas.translate((thumbLeft + thumbRight) / 2 - switchText.getWidth() / 2, (switchInnerTop + switchInnerBottom)
/ 2 - switchText.getHeight() / 2);
switchText.draw(canvas);
canvas.restore();
}
@Override
protected void onLayout(final boolean changed, final int left, final int top, final int right, final int bottom) {
super.onLayout(changed, left, top, right, bottom);
mThumbPosition = isChecked() ? getThumbScrollRange() : 0;
final int switchRight = getWidth() - getPaddingRight();
final int switchLeft = switchRight - mSwitchWidth;
int switchTop = 0;
int switchBottom = 0;
switch (getGravity() & Gravity.VERTICAL_GRAVITY_MASK) {
default:
case Gravity.TOP:
switchTop = getPaddingTop();
switchBottom = switchTop + mSwitchHeight;
break;
case Gravity.CENTER_VERTICAL:
switchTop = (getPaddingTop() + getHeight() - getPaddingBottom()) / 2 - mSwitchHeight / 2;
switchBottom = switchTop + mSwitchHeight;
break;
case Gravity.BOTTOM:
switchBottom = getHeight() - getPaddingBottom();
switchTop = switchBottom - mSwitchHeight;
break;
}
mSwitchLeft = switchLeft;
mSwitchTop = switchTop;
mSwitchBottom = switchBottom;
mSwitchRight = switchRight;
}
@Override
protected boolean verifyDrawable(final Drawable who) {
return super.verifyDrawable(who) || who == mThumbDrawable || who == mTrackDrawable;
}
private void animateThumbToCheckedState(final boolean newCheckedState) {
setChecked(newCheckedState);
}
private void cancelSuperTouch(final MotionEvent ev) {
final MotionEvent cancel = MotionEvent.obtain(ev);
cancel.setAction(MotionEvent.ACTION_CANCEL);
super.onTouchEvent(cancel);
cancel.recycle();
}
private boolean getTargetCheckedState() {
return mThumbPosition >= getThumbScrollRange() / 2;
}
private int getThumbScrollRange() {
if (mTrackDrawable == null) return 0;
mTrackDrawable.getPadding(mTempRect);
return mSwitchWidth - mThumbWidth - mTempRect.left - mTempRect.right;
}
/**
* @return true if (x, y) is within the target area of the switch thumb
*/
private boolean hitThumb(final float x, final float y) {
mThumbDrawable.getPadding(mTempRect);
final int thumbTop = mSwitchTop - mTouchSlop;
final int thumbLeft = mSwitchLeft + (int) (mThumbPosition + 0.5f) - mTouchSlop;
final int thumbRight = thumbLeft + mThumbWidth + mTempRect.left + mTempRect.right + mTouchSlop;
final int thumbBottom = mSwitchBottom + mTouchSlop;
return x > thumbLeft && x < thumbRight && y > thumbTop && y < thumbBottom;
}
@SuppressLint("FloatMath")
private Layout makeLayout(final CharSequence text) {
return new StaticLayout(text, mTextPaint, (int) Math.ceil(Layout.getDesiredWidth(text, mTextPaint)),
Layout.Alignment.ALIGN_NORMAL, 1.f, 0, true);
}
/**
* Called from onTouchEvent to end a drag operation.
*
* @param ev Event that triggered the end of drag mode - ACTION_UP or
* ACTION_CANCEL
*/
private void stopDrag(final MotionEvent ev) {
mTouchMode = TOUCH_MODE_IDLE;
// Up and not canceled, also checks the switch has not been disabled
// during the drag
final boolean commitChange = ev.getAction() == MotionEvent.ACTION_UP && isEnabled();
cancelSuperTouch(ev);
if (commitChange) {
boolean newState;
mVelocityTracker.computeCurrentVelocity(1000);
final float xvel = mVelocityTracker.getXVelocity();
if (Math.abs(xvel) > mMinFlingVelocity) {
newState = xvel > 0;
} else {
newState = getTargetCheckedState();
}
animateThumbToCheckedState(newState);
} else {
animateThumbToCheckedState(isChecked());
}
}
}