/*
* Copyright (C) 2008 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.internal.widget;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
public class VerticalTextSpinner extends View {
private static final int SELECTOR_ARROW_HEIGHT = 15;
private static final int TEXT_SPACING = 18;
private static final int TEXT_MARGIN_RIGHT = 25;
private static final int TEXT_SIZE = 22;
/* Keep the calculations as this is really a for loop from
* -2 to 2 but precalculated so we don't have to do in the onDraw.
*/
private static final int TEXT1_Y = (TEXT_SIZE * (-2 + 2)) + (TEXT_SPACING * (-2 + 1));
private static final int TEXT2_Y = (TEXT_SIZE * (-1 + 2)) + (TEXT_SPACING * (-1 + 1));
private static final int TEXT3_Y = (TEXT_SIZE * (0 + 2)) + (TEXT_SPACING * (0 + 1));
private static final int TEXT4_Y = (TEXT_SIZE * (1 + 2)) + (TEXT_SPACING * (1 + 1));
private static final int TEXT5_Y = (TEXT_SIZE * (2 + 2)) + (TEXT_SPACING * (2 + 1));
private static final int SCROLL_MODE_NONE = 0;
private static final int SCROLL_MODE_UP = 1;
private static final int SCROLL_MODE_DOWN = 2;
private static final long DEFAULT_SCROLL_INTERVAL_MS = 400;
private static final int SCROLL_DISTANCE = TEXT_SIZE + TEXT_SPACING;
private static final int MIN_ANIMATIONS = 4;
private final Drawable mBackgroundFocused;
private final Drawable mSelectorFocused;
private final Drawable mSelectorNormal;
private final int mSelectorDefaultY;
private final int mSelectorMinY;
private final int mSelectorMaxY;
private final int mSelectorHeight;
private final TextPaint mTextPaintDark;
private final TextPaint mTextPaintLight;
private int mSelectorY;
private Drawable mSelector;
private int mDownY;
private boolean isDraggingSelector;
private int mScrollMode;
private long mScrollInterval;
private boolean mIsAnimationRunning;
private boolean mStopAnimation;
private boolean mWrapAround = true;
private int mTotalAnimatedDistance;
private int mNumberOfAnimations;
private long mDelayBetweenAnimations;
private int mDistanceOfEachAnimation;
private String[] mTextList;
private int mCurrentSelectedPos;
private OnChangedListener mListener;
private String mText1;
private String mText2;
private String mText3;
private String mText4;
private String mText5;
public interface OnChangedListener {
void onChanged(
VerticalTextSpinner spinner, int oldPos, int newPos, String[] items);
}
public VerticalTextSpinner(Context context) {
this(context, null);
}
public VerticalTextSpinner(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public VerticalTextSpinner(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
mBackgroundFocused = context.getResources().getDrawable(com.android.internal.R.drawable.pickerbox_background);
mSelectorFocused = context.getResources().getDrawable(com.android.internal.R.drawable.pickerbox_selected);
mSelectorNormal = context.getResources().getDrawable(com.android.internal.R.drawable.pickerbox_unselected);
mSelectorHeight = mSelectorFocused.getIntrinsicHeight();
mSelectorDefaultY = (mBackgroundFocused.getIntrinsicHeight() - mSelectorHeight) / 2;
mSelectorMinY = 0;
mSelectorMaxY = mBackgroundFocused.getIntrinsicHeight() - mSelectorHeight;
mSelector = mSelectorNormal;
mSelectorY = mSelectorDefaultY;
mTextPaintDark = new TextPaint(Paint.ANTI_ALIAS_FLAG);
mTextPaintDark.setTextSize(TEXT_SIZE);
mTextPaintDark.setColor(context.getResources().getColor(com.android.internal.R.color.primary_text_light));
mTextPaintLight = new TextPaint(Paint.ANTI_ALIAS_FLAG);
mTextPaintLight.setTextSize(TEXT_SIZE);
mTextPaintLight.setColor(context.getResources().getColor(com.android.internal.R.color.secondary_text_dark));
mScrollMode = SCROLL_MODE_NONE;
mScrollInterval = DEFAULT_SCROLL_INTERVAL_MS;
calculateAnimationValues();
}
public void setOnChangeListener(OnChangedListener listener) {
mListener = listener;
}
public void setItems(String[] textList) {
mTextList = textList;
calculateTextPositions();
}
public void setSelectedPos(int selectedPos) {
mCurrentSelectedPos = selectedPos;
calculateTextPositions();
postInvalidate();
}
public void setScrollInterval(long interval) {
mScrollInterval = interval;
calculateAnimationValues();
}
public void setWrapAround(boolean wrap) {
mWrapAround = wrap;
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
/* This is a bit confusing, when we get the key event
* DPAD_DOWN we actually roll the spinner up. When the
* key event is DPAD_UP we roll the spinner down.
*/
if ((keyCode == KeyEvent.KEYCODE_DPAD_UP) && canScrollDown()) {
mScrollMode = SCROLL_MODE_DOWN;
scroll();
mStopAnimation = true;
return true;
} else if ((keyCode == KeyEvent.KEYCODE_DPAD_DOWN) && canScrollUp()) {
mScrollMode = SCROLL_MODE_UP;
scroll();
mStopAnimation = true;
return true;
}
return super.onKeyDown(keyCode, event);
}
private boolean canScrollDown() {
return (mCurrentSelectedPos > 0) || mWrapAround;
}
private boolean canScrollUp() {
return ((mCurrentSelectedPos < (mTextList.length - 1)) || mWrapAround);
}
@Override
protected void onFocusChanged(boolean gainFocus, int direction,
Rect previouslyFocusedRect) {
if (gainFocus) {
setBackgroundDrawable(mBackgroundFocused);
mSelector = mSelectorFocused;
} else {
setBackgroundDrawable(null);
mSelector = mSelectorNormal;
mSelectorY = mSelectorDefaultY;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
final int action = event.getAction();
final int y = (int) event.getY();
switch (action) {
case MotionEvent.ACTION_DOWN:
requestFocus();
mDownY = y;
isDraggingSelector = (y >= mSelectorY) && (y <= (mSelectorY + mSelector.getIntrinsicHeight()));
break;
case MotionEvent.ACTION_MOVE:
if (isDraggingSelector) {
int top = mSelectorDefaultY + (y - mDownY);
if (top <= mSelectorMinY && canScrollDown()) {
mSelectorY = mSelectorMinY;
mStopAnimation = false;
if (mScrollMode != SCROLL_MODE_DOWN) {
mScrollMode = SCROLL_MODE_DOWN;
scroll();
}
} else if (top >= mSelectorMaxY && canScrollUp()) {
mSelectorY = mSelectorMaxY;
mStopAnimation = false;
if (mScrollMode != SCROLL_MODE_UP) {
mScrollMode = SCROLL_MODE_UP;
scroll();
}
} else {
mSelectorY = top;
mStopAnimation = true;
}
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
default:
mSelectorY = mSelectorDefaultY;
mStopAnimation = true;
invalidate();
break;
}
return true;
}
@Override
protected void onDraw(Canvas canvas) {
/* The bounds of the selector */
final int selectorLeft = 0;
final int selectorTop = mSelectorY;
final int selectorRight = mMeasuredWidth;
final int selectorBottom = mSelectorY + mSelectorHeight;
/* Draw the selector */
mSelector.setBounds(selectorLeft, selectorTop, selectorRight, selectorBottom);
mSelector.draw(canvas);
if (mTextList == null) {
/* We're not setup with values so don't draw anything else */
return;
}
final TextPaint textPaintDark = mTextPaintDark;
if (hasFocus()) {
/* The bounds of the top area where the text should be light */
final int topLeft = 0;
final int topTop = 0;
final int topRight = selectorRight;
final int topBottom = selectorTop + SELECTOR_ARROW_HEIGHT;
/* Assign a bunch of local finals for performance */
final String text1 = mText1;
final String text2 = mText2;
final String text3 = mText3;
final String text4 = mText4;
final String text5 = mText5;
final TextPaint textPaintLight = mTextPaintLight;
/*
* Draw the 1st, 2nd and 3rd item in light only, clip it so it only
* draws in the area above the selector
*/
canvas.save();
canvas.clipRect(topLeft, topTop, topRight, topBottom);
drawText(canvas, text1, TEXT1_Y
+ mTotalAnimatedDistance, textPaintLight);
drawText(canvas, text2, TEXT2_Y
+ mTotalAnimatedDistance, textPaintLight);
drawText(canvas, text3,
TEXT3_Y + mTotalAnimatedDistance, textPaintLight);
canvas.restore();
/*
* Draw the 2nd, 3rd and 4th clipped to the selector bounds in dark
* paint
*/
canvas.save();
canvas.clipRect(selectorLeft, selectorTop + SELECTOR_ARROW_HEIGHT,
selectorRight, selectorBottom - SELECTOR_ARROW_HEIGHT);
drawText(canvas, text2, TEXT2_Y
+ mTotalAnimatedDistance, textPaintDark);
drawText(canvas, text3,
TEXT3_Y + mTotalAnimatedDistance, textPaintDark);
drawText(canvas, text4,
TEXT4_Y + mTotalAnimatedDistance, textPaintDark);
canvas.restore();
/* The bounds of the bottom area where the text should be light */
final int bottomLeft = 0;
final int bottomTop = selectorBottom - SELECTOR_ARROW_HEIGHT;
final int bottomRight = selectorRight;
final int bottomBottom = mMeasuredHeight;
/*
* Draw the 3rd, 4th and 5th in white text, clip it so it only draws
* in the area below the selector.
*/
canvas.save();
canvas.clipRect(bottomLeft, bottomTop, bottomRight, bottomBottom);
drawText(canvas, text3,
TEXT3_Y + mTotalAnimatedDistance, textPaintLight);
drawText(canvas, text4,
TEXT4_Y + mTotalAnimatedDistance, textPaintLight);
drawText(canvas, text5,
TEXT5_Y + mTotalAnimatedDistance, textPaintLight);
canvas.restore();
} else {
drawText(canvas, mText3, TEXT3_Y, textPaintDark);
}
if (mIsAnimationRunning) {
if ((Math.abs(mTotalAnimatedDistance) + mDistanceOfEachAnimation) > SCROLL_DISTANCE) {
mTotalAnimatedDistance = 0;
if (mScrollMode == SCROLL_MODE_UP) {
int oldPos = mCurrentSelectedPos;
int newPos = getNewIndex(1);
if (newPos >= 0) {
mCurrentSelectedPos = newPos;
if (mListener != null) {
mListener.onChanged(this, oldPos, mCurrentSelectedPos, mTextList);
}
}
if (newPos < 0 || ((newPos >= mTextList.length - 1) && !mWrapAround)) {
mStopAnimation = true;
}
calculateTextPositions();
} else if (mScrollMode == SCROLL_MODE_DOWN) {
int oldPos = mCurrentSelectedPos;
int newPos = getNewIndex(-1);
if (newPos >= 0) {
mCurrentSelectedPos = newPos;
if (mListener != null) {
mListener.onChanged(this, oldPos, mCurrentSelectedPos, mTextList);
}
}
if (newPos < 0 || (newPos == 0 && !mWrapAround)) {
mStopAnimation = true;
}
calculateTextPositions();
}
if (mStopAnimation) {
final int previousScrollMode = mScrollMode;
/* No longer scrolling, we wait till the current animation
* completes then we stop.
*/
mIsAnimationRunning = false;
mStopAnimation = false;
mScrollMode = SCROLL_MODE_NONE;
/* If the current selected item is an empty string
* scroll past it.
*/
if ("".equals(mTextList[mCurrentSelectedPos])) {
mScrollMode = previousScrollMode;
scroll();
mStopAnimation = true;
}
}
} else {
if (mScrollMode == SCROLL_MODE_UP) {
mTotalAnimatedDistance -= mDistanceOfEachAnimation;
} else if (mScrollMode == SCROLL_MODE_DOWN) {
mTotalAnimatedDistance += mDistanceOfEachAnimation;
}
}
if (mDelayBetweenAnimations > 0) {
postInvalidateDelayed(mDelayBetweenAnimations);
} else {
invalidate();
}
}
}
/**
* Called every time the text items or current position
* changes. We calculate store we don't have to calculate
* onDraw.
*/
private void calculateTextPositions() {
mText1 = getTextToDraw(-2);
mText2 = getTextToDraw(-1);
mText3 = getTextToDraw(0);
mText4 = getTextToDraw(1);
mText5 = getTextToDraw(2);
}
private String getTextToDraw(int offset) {
int index = getNewIndex(offset);
if (index < 0) {
return "";
}
return mTextList[index];
}
private int getNewIndex(int offset) {
int index = mCurrentSelectedPos + offset;
if (index < 0) {
if (mWrapAround) {
index += mTextList.length;
} else {
return -1;
}
} else if (index >= mTextList.length) {
if (mWrapAround) {
index -= mTextList.length;
} else {
return -1;
}
}
return index;
}
private void scroll() {
if (mIsAnimationRunning) {
return;
}
mTotalAnimatedDistance = 0;
mIsAnimationRunning = true;
invalidate();
}
private void calculateAnimationValues() {
mNumberOfAnimations = (int) mScrollInterval / SCROLL_DISTANCE;
if (mNumberOfAnimations < MIN_ANIMATIONS) {
mNumberOfAnimations = MIN_ANIMATIONS;
mDistanceOfEachAnimation = SCROLL_DISTANCE / mNumberOfAnimations;
mDelayBetweenAnimations = 0;
} else {
mDistanceOfEachAnimation = SCROLL_DISTANCE / mNumberOfAnimations;
mDelayBetweenAnimations = mScrollInterval / mNumberOfAnimations;
}
}
private void drawText(Canvas canvas, String text, int y, TextPaint paint) {
int width = (int) paint.measureText(text);
int x = getMeasuredWidth() - width - TEXT_MARGIN_RIGHT;
canvas.drawText(text, x, y, paint);
}
public int getCurrentSelectedPos() {
return mCurrentSelectedPos;
}
}
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