Java tutorial
/* * * MIT License * * Copyright (c) 2017 Alibaba Group * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * */ package com.qs.qswlw.view.Mypager; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Paint; import android.support.v4.view.ViewPager; import android.util.AttributeSet; import android.util.TypedValue; import android.view.Gravity; import android.view.View; /** * Created by mikeafc on 15/11/25. */ public class UltraViewPagerIndicator extends View implements ViewPager.OnPageChangeListener, IUltraIndicatorBuilder { interface UltraViewPagerIndicatorListener { void build(); } private UltraViewPagerView viewPager; private ViewPager.OnPageChangeListener pageChangeListener; private int scrollState; //attr for custom private int radius; private int indicatorPadding; private boolean animateIndicator; private int gravity; private UltraViewPager.Orientation orientation = UltraViewPager.Orientation.HORIZONTAL; private int marginLeft; private int marginTop; private int marginRight; private int marginBottom; //for circle private int focusColor; private int normalColor; //for custom icon private Bitmap focusBitmap; private Bitmap normalBitmap; //paint private Paint paintStroke; private Paint paintFill; float pageOffset; float defaultRadius; //default private static final int DEFAULT_RADIUS = 3; private UltraViewPagerIndicatorListener indicatorBuildListener; public UltraViewPagerIndicator(Context context) { super(context); init(); } public UltraViewPagerIndicator(Context context, AttributeSet attrs) { super(context, attrs); init(); } public UltraViewPagerIndicator(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { paintStroke = new Paint(Paint.ANTI_ALIAS_FLAG); paintStroke.setStyle(Paint.Style.STROKE); paintFill = new Paint(Paint.ANTI_ALIAS_FLAG); paintFill.setStyle(Paint.Style.FILL); defaultRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, DEFAULT_RADIUS, getResources().getDisplayMetrics()); } public void setViewPager(UltraViewPagerView viewPager) { this.viewPager = viewPager; this.viewPager.setOnPageChangeListener(this); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (viewPager == null || viewPager.getAdapter() == null) return; final int count = ((UltraViewPagerAdapter) viewPager.getAdapter()).getRealCount(); if (count == 0) return; int longSize; int shortSize; int longPaddingBefore; int longPaddingAfter; int shortPaddingBefore; int shortPaddingAfter; if (orientation == UltraViewPager.Orientation.HORIZONTAL) { longSize = viewPager.getWidth(); shortSize = viewPager.getHeight(); longPaddingBefore = (int) (getItemWidth() + getPaddingLeft() + marginLeft); longPaddingAfter = getPaddingRight() + marginRight; shortPaddingBefore = (int) (getItemWidth() + getPaddingTop() + marginTop); shortPaddingAfter = (int) paintStroke.getStrokeWidth() + getPaddingBottom() + marginBottom; } else { longSize = viewPager.getHeight(); shortSize = viewPager.getWidth(); longPaddingBefore = (int) (getItemWidth() + getPaddingTop() + marginTop); longPaddingAfter = (int) paintStroke.getStrokeWidth() + getPaddingBottom() + marginBottom; shortPaddingBefore = (int) (getItemWidth() + getPaddingLeft() + marginLeft); shortPaddingAfter = getPaddingRight() + marginRight; } final float itemWidth = getItemWidth(); final int widthRatio = isDrawResIndicator() ? 1 : 2; //bitmap resource X1 : circle X2 if (indicatorPadding == 0) { indicatorPadding = (int) itemWidth; } float shortOffset = shortPaddingBefore; float longOffset = longPaddingBefore; final float indicatorLength = count * itemWidth * widthRatio + (count - 1) * indicatorPadding; final int horizontalGravityMask = gravity & Gravity.HORIZONTAL_GRAVITY_MASK; final int verticalGravityMask = gravity & Gravity.VERTICAL_GRAVITY_MASK; switch (horizontalGravityMask) { case Gravity.CENTER_HORIZONTAL: longOffset = (longSize - longPaddingBefore - longPaddingAfter - indicatorLength) / 2.0f; break; case Gravity.RIGHT: if (orientation == UltraViewPager.Orientation.HORIZONTAL) { longOffset = longSize - longPaddingAfter - indicatorLength; } if (orientation == UltraViewPager.Orientation.VERTICAL) { shortOffset = shortSize - shortPaddingAfter - itemWidth; } break; case Gravity.LEFT: default: break; } switch (verticalGravityMask) { case Gravity.CENTER_VERTICAL: shortOffset = (shortSize - shortPaddingAfter - shortPaddingBefore - itemWidth) / 2; break; case Gravity.BOTTOM: if (orientation == UltraViewPager.Orientation.HORIZONTAL) { shortOffset = shortSize - shortPaddingAfter - getItemHeight(); } if (orientation == UltraViewPager.Orientation.VERTICAL) { longOffset = longSize - longPaddingAfter - indicatorLength; } break; case Gravity.TOP: default: break; } if (horizontalGravityMask == Gravity.CENTER_HORIZONTAL && verticalGravityMask == Gravity.CENTER_VERTICAL) { shortOffset = (shortSize - shortPaddingAfter - shortPaddingBefore - itemWidth) / 2; } float dX; float dY; float pageFillRadius = radius; if (paintStroke.getStrokeWidth() > 0) { pageFillRadius -= paintStroke.getStrokeWidth() / 2.0f; //TODO may not/2 } //Draw stroked circles for (int iLoop = 0; iLoop < count; iLoop++) { float drawLong = longOffset + (iLoop * (itemWidth * widthRatio + indicatorPadding)); if (orientation == UltraViewPager.Orientation.HORIZONTAL) { dX = drawLong; dY = shortOffset; } else { dX = shortOffset; dY = drawLong; } if (isDrawResIndicator()) { if (iLoop == viewPager.getCurrentItem()) continue; canvas.drawBitmap(normalBitmap, dX, dY, paintFill); } else { // Only paint fill if not completely transparent if (paintFill.getAlpha() > 0) { paintFill.setColor(normalColor); canvas.drawCircle(dX, dY, pageFillRadius, paintFill); } // Only paint stroke if a stroke width was non-zero if (pageFillRadius != radius) { canvas.drawCircle(dX, dY, radius, paintStroke); } } } //Draw the filled circle according to the current scroll float cx = (viewPager.getCurrentItem()) * (itemWidth * widthRatio + indicatorPadding); if (animateIndicator) cx += pageOffset * itemWidth; if (orientation == UltraViewPager.Orientation.HORIZONTAL) { dX = longOffset + cx; dY = shortOffset; } else { dX = shortOffset; dY = longOffset + cx; } if (isDrawResIndicator()) { canvas.drawBitmap(focusBitmap, dX, dY, paintStroke); } else { paintFill.setColor(focusColor); canvas.drawCircle(dX, dY, radius, paintFill); } } private boolean isDrawResIndicator() { return focusBitmap != null && normalBitmap != null; } private float getItemWidth() { if (isDrawResIndicator()) { return Math.max(focusBitmap.getWidth(), normalBitmap.getWidth()); } return radius == 0 ? defaultRadius : radius; } private float getItemHeight() { if (isDrawResIndicator()) { return Math.max(focusBitmap.getHeight(), normalBitmap.getHeight()); } return radius == 0 ? defaultRadius : radius; } @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { pageOffset = positionOffset; invalidate(); if (pageChangeListener != null) { pageChangeListener.onPageScrolled(position, positionOffset, positionOffsetPixels); } } @Override public void onPageSelected(int position) { if (scrollState == ViewPager.SCROLL_STATE_IDLE) { invalidate(); } if (pageChangeListener != null) { pageChangeListener.onPageSelected(position); } } @Override public void onPageScrollStateChanged(int state) { scrollState = state; if (pageChangeListener != null) { pageChangeListener.onPageScrollStateChanged(state); } } @Override public IUltraIndicatorBuilder setOrientation(UltraViewPager.Orientation orien) { this.orientation = orien; return this; } @Override public IUltraIndicatorBuilder setRadius(int radius) { this.radius = radius; return this; } @Override public IUltraIndicatorBuilder setIndicatorPadding(int indicatorPadding) { this.indicatorPadding = indicatorPadding; return this; } @Override public IUltraIndicatorBuilder setFocusColor(int focusColor) { this.focusColor = focusColor; return this; } @Override public IUltraIndicatorBuilder setNormalColor(int normalColor) { this.normalColor = normalColor; return this; } @Override public IUltraIndicatorBuilder setStrokeColor(int strokeColor) { paintStroke.setColor(strokeColor); return this; } @Override public IUltraIndicatorBuilder setStrokeWidth(int strokeWidth) { paintStroke.setStrokeWidth(strokeWidth); return this; } @Override public IUltraIndicatorBuilder setGravity(int gravity) { this.gravity = gravity; return this; } @Override public IUltraIndicatorBuilder setFocusResId(int focusResId) { try { focusBitmap = BitmapFactory.decodeResource(getResources(), focusResId); } catch (Exception e) { e.printStackTrace(); } return this; } @Override public IUltraIndicatorBuilder setNormalResId(int normalResId) { try { normalBitmap = BitmapFactory.decodeResource(getResources(), normalResId); } catch (Exception e) { e.printStackTrace(); } return this; } @Override public IUltraIndicatorBuilder setFocusIcon(Bitmap bitmap) { focusBitmap = bitmap; return this; } @Override public IUltraIndicatorBuilder setNormalIcon(Bitmap bitmap) { normalBitmap = bitmap; return this; } @Override public IUltraIndicatorBuilder setMargin(int left, int top, int right, int bottom) { marginLeft = left; marginTop = top; marginRight = right; marginBottom = bottom; return this; } @Override public void build() { if (indicatorBuildListener != null) { indicatorBuildListener.build(); } } public void setPageChangeListener(ViewPager.OnPageChangeListener pageChangeListener) { this.pageChangeListener = pageChangeListener; } public void setIndicatorBuildListener(UltraViewPagerIndicatorListener listener) { this.indicatorBuildListener = listener; } }