package com.lling.qiqu.ui;
import java.util.ArrayList;
import java.util.List;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import com.lling.qiqu.R;
/**
* @ClassName: CategoryTabStrip
* @Description: 频道展示的HorizontalScrollView
* @author lling
* @date 2015年6月2日
*/
@SuppressLint("NewApi")
public class CategoryTabStrip extends LinearLayout {
private LayoutInflater mLayoutInflater;
private final PageListener pageListener = new PageListener();
private ViewPager pager;
private LinearLayout tabsContainer;
private int tabCount;
private int currentPosition = 0;
private float currentPositionOffset = 0f;
private Rect indicatorRect;
private LinearLayout.LayoutParams defaultTabLayoutParams;
private int scrollOffset = 0;
private int lastScrollX = 0;
private Drawable indicator;
private TextDrawable[] drawables;
public CategoryTabStrip(Context context) {
this(context, null);
}
public CategoryTabStrip(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CategoryTabStrip(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mLayoutInflater = LayoutInflater.from(context);
drawables = new TextDrawable[3];
int i = 0;
while (i < drawables.length) {
drawables[i] = new TextDrawable(getContext());
i++;
}
indicatorRect = new Rect();
// setFillViewport(true);
setWillNotDraw(false);
tabsContainer = new LinearLayout(context);
tabsContainer.setOrientation(LinearLayout.HORIZONTAL);
tabsContainer.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
addView(tabsContainer);
DisplayMetrics dm = getResources().getDisplayMetrics();
scrollOffset = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, scrollOffset, dm);
defaultTabLayoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
// 绘制高亮区域作为滑动分页指示器
indicator = getResources().getDrawable(R.drawable.bg_category_indicator);
// indicator = getResources().getDrawable(R.drawable.indicator_underline);
// 左右边界阴影效果
}
// 绑定与CategoryTabStrip控件对应的ViewPager控件，实现联动
public void setViewPager(ViewPager pager) {
this.pager = pager;
if (pager.getAdapter() == null) {
throw new IllegalStateException("ViewPager does not have adapter instance.");
}
pager.setOnPageChangeListener(pageListener);
// notifyDataSetChanged();
}
// 当附加在ViewPager适配器上的数据发生变化时,应该调用该方法通知CategoryTabStrip刷新数据
public void notifyDataSetChanged() {
tabsContainer.removeAllViews();
// tabCount = pager.getAdapter().getCount();
tabCount = catalogs.size();
for (int i = 0; i < tabCount; i++) {
addTab(i, catalogs.get(i).toString());
}
}
private void addTab(final int position, String title) {
ViewGroup tab = (ViewGroup)mLayoutInflater.inflate(R.layout.category_tab, this, false);
TextView category_text = (TextView) tab.findViewById(R.id.category_text);
category_text.setText(title);
category_text.setGravity(Gravity.CENTER);
category_text.setSingleLine();
category_text.setFocusable(true);
// category_text.setTextColor(getResources().getColor(R.color.big_title));
tab.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
pager.setCurrentItem(position);
}
});
tabsContainer.addView(tab, position, defaultTabLayoutParams);
}
// 计算滑动过程中矩形高亮区域的上下左右位置
private void calculateIndicatorRect(Rect rect) {
ViewGroup currentTab = (ViewGroup)tabsContainer.getChildAt(currentPosition);
TextView category_text = (TextView) currentTab.findViewById(R.id.category_text);
float left = (float) (currentTab.getLeft() + category_text.getLeft());
float width = ((float) category_text.getWidth()) + left;
if (currentPositionOffset > 0f && currentPosition < tabCount - 1) {
ViewGroup nextTab = (ViewGroup)tabsContainer.getChildAt(currentPosition + 1);
TextView next_category_text = (TextView) nextTab.findViewById(R.id.category_text);
float next_left = (float) (nextTab.getLeft() + next_category_text.getLeft());
left = left * (1.0f - currentPositionOffset) + next_left * currentPositionOffset;
width = width * (1.0f - currentPositionOffset) + currentPositionOffset * (((float) next_category_text.getWidth()) + next_left);
}
rect.set(((int) left) + getPaddingLeft(), getPaddingTop() + currentTab.getTop() + category_text.getTop(),
((int) width) + getPaddingLeft(), currentTab.getTop() + getPaddingTop() + category_text.getTop() + category_text.getHeight());
}
// 计算滚动范围
private int getScrollRange() {
return getChildCount() > 0 ? Math.max(0, getChildAt(0).getWidth() - getWidth() + getPaddingLeft() + getPaddingRight()) : 0;
}
private void scrollToChild(int position, int offset) {
if (tabCount == 0) {
return;
}
calculateIndicatorRect(indicatorRect);
int newScrollX = lastScrollX;
if (indicatorRect.left < getScrollX() + scrollOffset) {
newScrollX = indicatorRect.left - scrollOffset;
} else if (indicatorRect.right > getScrollX() + getWidth() - scrollOffset) {
newScrollX = indicatorRect.right - getWidth() + scrollOffset;
}
if (newScrollX != lastScrollX) {
lastScrollX = newScrollX;
scrollTo(newScrollX, 0);
}
}
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
calculateIndicatorRect(indicatorRect);
if(indicator != null) {
indicator.setBounds(indicatorRect);
indicator.draw(canvas);
}
int i = 0;
while (i < tabsContainer.getChildCount()) {
if (i < currentPosition - 1 || i > currentPosition + 1) {
i++;
} else {
ViewGroup tab = (ViewGroup)tabsContainer.getChildAt(i);
TextView category_text = (TextView) tab.findViewById(R.id.category_text);
if (category_text != null) {
TextDrawable textDrawable = drawables[i - currentPosition + 1];
int save = canvas.save();
calculateIndicatorRect(indicatorRect);
canvas.clipRect(indicatorRect);
textDrawable.setText(category_text.getText());
textDrawable.setTextSize(0, category_text.getTextSize());
textDrawable.setTextColor(getResources().getColor(R.color.main_color));
int left = tab.getLeft() + category_text.getLeft() + (category_text.getWidth() - textDrawable.getIntrinsicWidth()) / 2 + getPaddingLeft();
int top = tab.getTop() + category_text.getTop() + (category_text.getHeight() - textDrawable.getIntrinsicHeight()) / 2 + getPaddingTop();
textDrawable.setBounds(left, top, textDrawable.getIntrinsicWidth() + left, textDrawable.getIntrinsicHeight() + top);
textDrawable.draw(canvas);
canvas.restoreToCount(save);
}
i++;
}
}
}
private class PageListener implements OnPageChangeListener {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
currentPosition = position;
currentPositionOffset = positionOffset;
scrollToChild(position, (int) (positionOffset * tabsContainer.getChildAt(position).getWidth()));
invalidate();
}
@Override
public void onPageScrollStateChanged(int state) {
if (state == ViewPager.SCROLL_STATE_IDLE) {
if(pager.getCurrentItem() == 0) {
// 滑动到最左边
scrollTo(0, 0);
} else if (pager.getCurrentItem() == tabCount - 1) {
// 滑动到最右边
scrollTo(getScrollRange(), 0);
} else {
scrollToChild(pager.getCurrentItem(), 0);
}
}
}
@Override
public void onPageSelected(int position) {
}
}
private List<String> catalogs = new ArrayList<String>();
public void setCatalogs(List<String> catalogs) {
this.catalogs = catalogs;
notifyDataSetChanged();
if(currentPosition > catalogs.size()-1) {
currentPosition = catalogs.size()-1;
}
pager.setCurrentItem(currentPosition);
}
}
