/*
* Copyright (C) 2011 Patrik Akerfeldt
* Copyright (C) 2011 Francisco Figueiredo Jr.
* Copyright (C) 2011 Jake Wharton
*
* 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.viewpagerindicator;
import java.util.ArrayList;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
/**
* A TitlePageIndicator is a PageIndicator which displays the title of left view
* (if exist), the title of the current select view (centered) and the title of
* the right view (if exist). When the user scrolls the ViewPager then titles are
* also scrolled.
*/
public class TitlePageIndicator extends View implements PageIndicator {
/**
* Percentage indicating what percentage of the screen width away from
* center should the underline be fully faded. A value of 0.25 means that
* halfway between the center of the screen and an edge.
*/
private static final float SELECTION_FADE_PERCENTAGE = 0.25f;
/**
* Percentage indicating what percentage of the screen width away from
* center should the selected text bold turn off. A value of 0.05 means
* that 10% between the center and an edge.
*/
private static final float BOLD_FADE_PERCENTAGE = 0.05f;
public enum IndicatorStyle {
None(0), Triangle(1), Underline(2);
public final int value;
private IndicatorStyle(int value) {
this.value = value;
}
public static IndicatorStyle fromValue(int value) {
for (IndicatorStyle style : IndicatorStyle.values()) {
if (style.value == value) {
return style;
}
}
return null;
}
}
private ViewPager mViewPager;
private ViewPager.OnPageChangeListener mListener;
private TitleProvider mTitleProvider;
private int mCurrentPage;
private int mCurrentOffset;
private int mScrollState;
private final Paint mPaintText;
private boolean mBoldText;
private int mColorText;
private int mColorSelected;
private Path mPath;
private final Paint mPaintFooterLine;
private IndicatorStyle mFooterIndicatorStyle;
private final Paint mPaintFooterIndicator;
private float mFooterIndicatorHeight;
private float mFooterIndicatorUnderlinePadding;
private float mFooterPadding;
private float mTitlePadding;
private float mTopPadding;
/** Left and right side padding for not active view titles. */
private float mClipPadding;
private float mFooterLineHeight;
public TitlePageIndicator(Context context) {
this(context, null);
}
public TitlePageIndicator(Context context, AttributeSet attrs) {
this(context, attrs, R.attr.titlePageIndicatorStyle);
}
public TitlePageIndicator(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
//Load defaults from resources
final Resources res = getResources();
final int defaultFooterColor = res.getColor(R.color.default_title_indicator_footer_color);
final float defaultFooterLineHeight = res.getDimension(R.dimen.default_title_indicator_footer_line_height);
final int defaultFooterIndicatorStyle = res.getInteger(R.integer.default_title_indicator_footer_indicator_style);
final float defaultFooterIndicatorHeight = res.getDimension(R.dimen.default_title_indicator_footer_indicator_height);
final float defaultFooterIndicatorUnderlinePadding = res.getDimension(R.dimen.default_title_indicator_footer_indicator_underline_padding);
final float defaultFooterPadding = res.getDimension(R.dimen.default_title_indicator_footer_padding);
final int defaultSelectedColor = res.getColor(R.color.default_title_indicator_selected_color);
final boolean defaultSelectedBold = res.getBoolean(R.bool.default_title_indicator_selected_bold);
final int defaultTextColor = res.getColor(R.color.default_title_indicator_text_color);
final float defaultTextSize = res.getDimension(R.dimen.default_title_indicator_text_size);
final float defaultTitlePadding = res.getDimension(R.dimen.default_title_indicator_title_padding);
final float defaultClipPadding = res.getDimension(R.dimen.default_title_indicator_clip_padding);
final float defaultTopPadding = res.getDimension(R.dimen.default_title_indicator_top_padding);
//Retrieve styles attributes
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.TitlePageIndicator, defStyle, R.style.Widget_TitlePageIndicator);
//Retrieve the colors to be used for this view and apply them.
mFooterLineHeight = a.getDimension(R.styleable.TitlePageIndicator_footerLineHeight, defaultFooterLineHeight);
mFooterIndicatorStyle = IndicatorStyle.fromValue(a.getInteger(R.styleable.TitlePageIndicator_footerIndicatorStyle, defaultFooterIndicatorStyle));
mFooterIndicatorHeight = a.getDimension(R.styleable.TitlePageIndicator_footerIndicatorHeight, defaultFooterIndicatorHeight);
mFooterIndicatorUnderlinePadding = a.getDimension(R.styleable.TitlePageIndicator_footerIndicatorUnderlinePadding, defaultFooterIndicatorUnderlinePadding);
mFooterPadding = a.getDimension(R.styleable.TitlePageIndicator_footerPadding, defaultFooterPadding);
mTopPadding = a.getDimension(R.styleable.TitlePageIndicator_topPadding, defaultTopPadding);
mTitlePadding = a.getDimension(R.styleable.TitlePageIndicator_titlePadding, defaultTitlePadding);
mClipPadding = a.getDimension(R.styleable.TitlePageIndicator_clipPadding, defaultClipPadding);
mColorSelected = a.getColor(R.styleable.TitlePageIndicator_selectedColor, defaultSelectedColor);
mColorText = a.getColor(R.styleable.TitlePageIndicator_textColor, defaultTextColor);
mBoldText = a.getBoolean(R.styleable.TitlePageIndicator_selectedBold, defaultSelectedBold);
final float textSize = a.getDimension(R.styleable.TitlePageIndicator_textSize, defaultTextSize);
final int footerColor = a.getColor(R.styleable.TitlePageIndicator_footerColor, defaultFooterColor);
mPaintText = new Paint();
mPaintText.setTextSize(textSize);
mPaintText.setAntiAlias(true);
mPaintFooterLine = new Paint();
mPaintFooterLine.setStyle(Paint.Style.FILL_AND_STROKE);
mPaintFooterLine.setStrokeWidth(mFooterLineHeight);
mPaintFooterLine.setColor(footerColor);
mPaintFooterIndicator = new Paint();
mPaintFooterIndicator.setStyle(Paint.Style.FILL_AND_STROKE);
mPaintFooterIndicator.setColor(footerColor);
a.recycle();
}
public int getFooterColor() {
return mPaintFooterLine.getColor();
}
public void setFooterColor(int footerColor) {
mPaintFooterLine.setColor(footerColor);
mPaintFooterIndicator.setColor(footerColor);
invalidate();
}
public float getFooterLineHeight() {
return mFooterLineHeight;
}
public void setFooterLineHeight(float footerLineHeight) {
mFooterLineHeight = footerLineHeight;
mPaintFooterLine.setStrokeWidth(mFooterLineHeight);
invalidate();
}
public float getFooterIndicatorHeight() {
return mFooterIndicatorHeight;
}
public void setFooterIndicatorHeight(float footerTriangleHeight) {
mFooterIndicatorHeight = footerTriangleHeight;
invalidate();
}
public float getFooterIndicatorPadding() {
return mFooterPadding;
}
public void setFooterIndicatorPadding(float footerIndicatorPadding) {
mFooterPadding = footerIndicatorPadding;
invalidate();
}
public IndicatorStyle getFooterIndicatorStyle() {
return mFooterIndicatorStyle;
}
public void setFooterIndicatorStyle(IndicatorStyle indicatorStyle) {
mFooterIndicatorStyle = indicatorStyle;
invalidate();
}
public int getSelectedColor() {
return mColorSelected;
}
public void setSelectedColor(int selectedColor) {
mColorSelected = selectedColor;
invalidate();
}
public boolean isSelectedBold() {
return mBoldText;
}
public void setSelectedBold(boolean selectedBold) {
mBoldText = selectedBold;
invalidate();
}
public int getTextColor() {
return mColorText;
}
public void setTextColor(int textColor) {
mPaintText.setColor(textColor);
mColorText = textColor;
invalidate();
}
public float getTextSize() {
return mPaintText.getTextSize();
}
public void setTextSize(float textSize) {
mPaintText.setTextSize(textSize);
invalidate();
}
public float getTitlePadding() {
return this.mTitlePadding;
}
public void setTitlePadding(float titlePadding) {
mTitlePadding = titlePadding;
invalidate();
}
public float getTopPadding() {
return this.mTopPadding;
}
public void setTopPadding(float topPadding) {
mTopPadding = topPadding;
invalidate();
}
public float getClipPadding() {
return this.mClipPadding;
}
public void setClipPadding(float clipPadding) {
mClipPadding = clipPadding;
invalidate();
}
/*
* (non-Javadoc)
*
* @see android.view.View#onDraw(android.graphics.Canvas)
*/
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//Calculate views bounds
ArrayList<RectF> bounds = calculateAllBounds(mPaintText);
final int count = mViewPager.getAdapter().getCount();
final int countMinusOne = count - 1;
final float halfWidth = getWidth() / 2f;
final int left = getLeft();
final float leftClip = left + mClipPadding;
final int width = getWidth();
final int height = getHeight();
final int right = left + width;
final float rightClip = right - mClipPadding;
int page = mCurrentPage;
float offsetPercent;
if (mCurrentOffset <= halfWidth) {
offsetPercent = 1.0f * mCurrentOffset / width;
} else {
page += 1;
offsetPercent = 1.0f * (width - mCurrentOffset) / width;
}
final boolean currentSelected = (offsetPercent <= SELECTION_FADE_PERCENTAGE);
final boolean currentBold = (offsetPercent <= BOLD_FADE_PERCENTAGE);
final float selectedPercent = (SELECTION_FADE_PERCENTAGE - offsetPercent) / SELECTION_FADE_PERCENTAGE;
//Verify if the current view must be clipped to the screen
RectF curPageBound = bounds.get(mCurrentPage);
float curPageWidth = curPageBound.right - curPageBound.left;
if (curPageBound.left < leftClip) {
//Try to clip to the screen (left side)
clipViewOnTheLeft(curPageBound, curPageWidth, left);
}
if (curPageBound.right > rightClip) {
//Try to clip to the screen (right side)
clipViewOnTheRight(curPageBound, curPageWidth, right);
}
//Left views starting from the current position
if (mCurrentPage > 0) {
for (int i = mCurrentPage - 1; i >= 0; i--) {
RectF bound = bounds.get(i);
//Is left side is outside the screen
if (bound.left < leftClip) {
float w = bound.right - bound.left;
//Try to clip to the screen (left side)
clipViewOnTheLeft(bound, w, left);
//Except if there's an intersection with the right view
RectF rightBound = bounds.get(i + 1);
//Intersection
if (bound.right + mTitlePadding > rightBound.left) {
bound.left = rightBound.left - w - mTitlePadding;
bound.right = bound.left + w;
}
}
}
}
//Right views starting from the current position
if (mCurrentPage < countMinusOne) {
for (int i = mCurrentPage + 1 ; i < count; i++) {
RectF bound = bounds.get(i);
//If right side is outside the screen
if (bound.right > rightClip) {
float w = bound.right - bound.left;
//Try to clip to the screen (right side)
clipViewOnTheRight(bound, w, right);
//Except if there's an intersection with the left view
RectF leftBound = bounds.get(i - 1);
//Intersection
if (bound.left - mTitlePadding < leftBound.right) {
bound.left = leftBound.right + mTitlePadding;
bound.right = bound.left + w;
}
}
}
}
//Now draw views
for (int i = 0; i < count; i++) {
//Get the title
RectF bound = bounds.get(i);
//Only if one side is visible
if ((bound.left > left && bound.left < right) || (bound.right > left && bound.right < right)) {
final boolean currentPage = (i == page);
//Only set bold if we are within bounds
mPaintText.setFakeBoldText(currentPage && currentBold && mBoldText);
//Draw text as unselected
mPaintText.setColor(mColorText);
canvas.drawText(mTitleProvider.getTitle(i), bound.left, bound.bottom + mTopPadding, mPaintText);
//If we are within the selected bounds draw the selected text
if (currentPage && currentSelected) {
mPaintText.setColor(mColorSelected);
mPaintText.setAlpha((int)((mColorSelected >>> 24) * selectedPercent));
canvas.drawText(mTitleProvider.getTitle(i), bound.left, bound.bottom + mTopPadding, mPaintText);
}
}
}
//Draw the footer line
mPath = new Path();
mPath.moveTo(0, height - mFooterLineHeight / 2f);
mPath.lineTo(width, height - mFooterLineHeight / 2f);
mPath.close();
canvas.drawPath(mPath, mPaintFooterLine);
switch (mFooterIndicatorStyle) {
case Triangle:
mPath = new Path();
mPath.moveTo(halfWidth, height - mFooterLineHeight - mFooterIndicatorHeight);
mPath.lineTo(halfWidth + mFooterIndicatorHeight, height - mFooterLineHeight);
mPath.lineTo(halfWidth - mFooterIndicatorHeight, height - mFooterLineHeight);
mPath.close();
canvas.drawPath(mPath, mPaintFooterIndicator);
break;
case Underline:
if (!currentSelected) {
break;
}
RectF underlineBounds = bounds.get(page);
mPath = new Path();
mPath.moveTo(underlineBounds.left - mFooterIndicatorUnderlinePadding, height - mFooterLineHeight);
mPath.lineTo(underlineBounds.right + mFooterIndicatorUnderlinePadding, height - mFooterLineHeight);
mPath.lineTo(underlineBounds.right + mFooterIndicatorUnderlinePadding, height - mFooterLineHeight - mFooterIndicatorHeight);
mPath.lineTo(underlineBounds.left - mFooterIndicatorUnderlinePadding, height - mFooterLineHeight - mFooterIndicatorHeight);
mPath.close();
mPaintFooterIndicator.setAlpha((int)(0xFF * selectedPercent));
canvas.drawPath(mPath, mPaintFooterIndicator);
mPaintFooterIndicator.setAlpha(0xFF);
break;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
final int count = mViewPager.getAdapter().getCount();
final int width = getWidth();
final float halfWidth = width / 2f;
final float sixthWidth = width / 6f;
if ((mCurrentPage > 0) && (event.getX() < halfWidth - sixthWidth)) {
mViewPager.setCurrentItem(mCurrentPage - 1);
return true;
} else if ((mCurrentPage < count - 1) && (event.getX() > halfWidth + sixthWidth)) {
mViewPager.setCurrentItem(mCurrentPage + 1);
return true;
}
}
return super.onTouchEvent(event);
}
/**
* Set bounds for the right textView including clip padding.
*
* @param curViewBound
* current bounds.
* @param curViewWidth
* width of the view.
*/
private void clipViewOnTheRight(RectF curViewBound, float curViewWidth, int right) {
curViewBound.right = right - mClipPadding;
curViewBound.left = curViewBound.right - curViewWidth;
}
/**
* Set bounds for the left textView including clip padding.
*
* @param curViewBound
* current bounds.
* @param curViewWidth
* width of the view.
*/
private void clipViewOnTheLeft(RectF curViewBound, float curViewWidth, int left) {
curViewBound.left = left + mClipPadding;
curViewBound.right = mClipPadding + curViewWidth;
}
/**
* Calculate views bounds and scroll them according to the current index
*
* @param paint
* @param currentIndex
* @return
*/
private ArrayList<RectF> calculateAllBounds(Paint paint) {
ArrayList<RectF> list = new ArrayList<RectF>();
//For each views (If no values then add a fake one)
final int count = mViewPager.getAdapter().getCount();
final int width = getWidth();
final int halfWidth = width / 2;
for (int i = 0; i < count; i++) {
RectF bounds = calcBounds(i, paint);
float w = (bounds.right - bounds.left);
float h = (bounds.bottom - bounds.top);
bounds.left = (halfWidth) - (w / 2) - mCurrentOffset + ((i - mCurrentPage) * width);
bounds.right = bounds.left + w;
bounds.top = 0;
bounds.bottom = h;
list.add(bounds);
}
return list;
}
/**
* Calculate the bounds for a view's title
*
* @param index
* @param paint
* @return
*/
private RectF calcBounds(int index, Paint paint) {
//Calculate the text bounds
RectF bounds = new RectF();
bounds.right = paint.measureText(mTitleProvider.getTitle(index));
bounds.bottom = paint.descent() - paint.ascent();
return bounds;
}
@Override
public void setViewPager(ViewPager view) {
if (view.getAdapter() == null) {
throw new IllegalStateException("ViewPager does not have adapter instance.");
}
if (!(view.getAdapter() instanceof TitleProvider)) {
throw new IllegalStateException("ViewPager adapter must implement TitleProvider to be used with TitlePageIndicator.");
}
mViewPager = view;
mViewPager.setOnPageChangeListener(this);
mTitleProvider = (TitleProvider)mViewPager.getAdapter();
invalidate();
}
@Override
public void setViewPager(ViewPager view, int initialPosition) {
setViewPager(view);
setCurrentItem(initialPosition);
}
@Override
public void setCurrentItem(int item) {
if (mViewPager == null) {
throw new IllegalStateException("ViewPager has not been bound.");
}
mViewPager.setCurrentItem(item);
mCurrentPage = item;
invalidate();
}
@Override
public void onPageScrollStateChanged(int state) {
mScrollState = state;
if (mListener != null) {
mListener.onPageScrollStateChanged(state);
}
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
mCurrentPage = position;
mCurrentOffset = positionOffsetPixels;
invalidate();
if (mListener != null) {
mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
}
}
@Override
public void onPageSelected(int position) {
if (mScrollState == ViewPager.SCROLL_STATE_IDLE) {
mCurrentPage = position;
invalidate();
}
if (mListener != null) {
mListener.onPageSelected(position);
}
}
@Override
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
mListener = listener;
}
/*
* (non-Javadoc)
*
* @see android.view.View#onMeasure(int, int)
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));
}
/**
* Determines the width of this view
*
* @param measureSpec
* A measureSpec packed into an int
* @return The width of the view, honoring constraints from measureSpec
*/
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException(getClass().getSimpleName() + " can only be used in EXACTLY mode.");
}
result = specSize;
return result;
}
/**
* Determines the height of this view
*
* @param measureSpec
* A measureSpec packed into an int
* @return The height of the view, honoring constraints from measureSpec
*/
private int measureHeight(int measureSpec) {
float result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
//We were told how big to be
result = specSize;
} else {
//Calculate the text bounds
RectF bounds = new RectF();
bounds.bottom = mPaintText.descent()-mPaintText.ascent();
result = bounds.bottom - bounds.top + mFooterLineHeight + mFooterPadding + mTopPadding;
if (mFooterIndicatorStyle != IndicatorStyle.None) {
result += mFooterIndicatorHeight;
}
}
return (int)result;
}
@Override
public void onRestoreInstanceState(Parcelable state) {
SavedState savedState = (SavedState)state;
super.onRestoreInstanceState(savedState.getSuperState());
mCurrentPage = savedState.currentPage;
requestLayout();
}
@Override
public Parcelable onSaveInstanceState() {
Parcelable superState = super.onSaveInstanceState();
SavedState savedState = new SavedState(superState);
savedState.currentPage = mCurrentPage;
return savedState;
}
static class SavedState extends BaseSavedState {
int currentPage;
public SavedState(Parcelable superState) {
super(superState);
}
private SavedState(Parcel in) {
super(in);
currentPage = in.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(currentPage);
}
public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
@Override
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
}