高仿今日头条（1）
直接贴代码：
@InjectView(android.R.id.tabcontent)
FrameLayout tabcontent;
@InjectView(android.R.id.tabs)
TabWidget tabs;
@InjectView(R.id.tabhost)
TabHost tabHost;
@InjectView(R.id.tab_home)
RadioButton tabHome;
@InjectView(R.id.tab_video)
RadioButton tabVideo;
@InjectView(R.id.tab_topic)
RadioButton tabTopic;
@InjectView(R.id.tab_mine)
RadioButton tabMine;
private Intent topic;
private Intent video;
private Intent news;
private Intent mine;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
flagBarTint(false);
setContentView(R.layout.activity_tabhost);
ButterKnife.inject(this);
// UIUtil.initTintMgr(this, tabs).setStatusBarTintColor(getResources().getColor(R.color.c9));
init(savedInstanceState);
}
private void init(Bundle savedInstanceState) {
LocalActivityManager groupActivity=new LocalActivityManager(this,
false);
groupActivity.dispatchCreate(savedInstanceState);
tabHost.setup(groupActivity);
initIntent();
addSpec();
((RadioGroup) findViewById(R.id.tab_radiogroup))
.setOnCheckedChangeListener(this);
}
private void initIntent() {
news=new Intent(this, NewsActivity.class);
video=new Intent(this, VideoActivity.class);
topic=new Intent(this, TopicActivity.class);
mine=new Intent(this, MineActivity.class);
}
private void addSpec() {
tabHost.addTab(this.buildTagSpec("home", R.string.xinwen,
R.drawable.home_selector, news));
tabHost.addTab(this.buildTagSpec("video", R.string.video,
R.drawable.video_selector, video));
tabHost.addTab(this.buildTagSpec("topic", R.string.topic,
R.drawable.topic_selector, topic));
tabHost.addTab(this.buildTagSpec("mine", R.string.me, R.drawable.mine_selector,
mine));
}
private TabHost.TabSpec buildTagSpec(String tagName, int string, int icon,
Intent content) {
return tabHost
.newTabSpec(tagName)
.setIndicator(getResources().getString(string),
getResources().getDrawable(icon)).setContent(content);
}
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
switch (checkedId) {
case R.id.tab_home:
tabHost.setCurrentTabByTag("home");
setCurrentChecked(tabHome);
break;
case R.id.tab_video:
tabHost.setCurrentTabByTag("video");
setCurrentChecked(tabVideo);
break;
case R.id.tab_topic:
tabHost.setCurrentTabByTag("topic");
setCurrentChecked(tabTopic);
break;
case R.id.tab_mine:
tabHost.setCurrentTabByTag("mine");
setCurrentChecked(tabMine);
break;
}
}
private void setCurrentChecked(RadioButton currentTab) {
tabHome.setTextColor(getResources().getColor(R.color.c6));
tabVideo.setTextColor(getResources().getColor(R.color.c6));
tabTopic.setTextColor(getResources().getColor(R.color.c6));
tabMine.setTextColor(getResources().getColor(R.color.c6));
currentTab.setTextColor(getResources().getColor(R.color.c9));
}
boolean doubleBackToExitPressedOnce=false;
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce=true;
Toast.makeText(this, "再按一次退出网易新闻", Toast.LENGTH_SHORT).show();
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce=false;
}
}, 2000);
}
主要看一下我自己封装的TabStrip，
public class TabStrip extends HorizontalScrollView {
public interface IconTabProvider {
public int getPageIconResId(int position);
}
private static final int[] ATTRS=new int[]{
android.R.attr.textSize,
android.R.attr.textColor
};
private LinearLayout.LayoutParams defaultTabLayoutParams;
private LinearLayout.LayoutParams expandedTabLayoutParams;
private final PageListener pageListener=new PageListener();
public OnPageChangeListener delegatePageListener;
private LinearLayout tabsContainer;
private ViewPager pager;
private int tabCount;
private int currentPosition=0;
private int tabCurrentPosition=0;
private float currentPositionOffset=0f;
private Paint rectPaint;
private int indicatorColor=0xFF666666;
private int underlineColor=0x1A000000;
private int tabTextColor=0xFF666666;
private int tabCheckTextColor=0xFF666666;
private boolean shouldExpand=false;
private int scrollOffset=52;
private int indicatorHeight=8;
private int underlineHeight=2;
private int tabPadding=20;
private int tabTextSize=14;
private Typeface tabTypeface=null;
private int tabTypefaceStyle=Typeface.BOLD;
private int lastScrollX=0;
private Locale locale;
public TabStrip(Context context) {
this(context, null);
}
public TabStrip(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public TabStrip(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
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);
indicatorHeight=(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, indicatorHeight, dm);
underlineHeight=(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, underlineHeight, dm);
tabPadding=(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, tabPadding, dm);
tabTextSize=(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, tabTextSize, dm);
TypedArray a=context.obtainStyledAttributes(attrs, ATTRS);
tabTextSize=a.getDimensionPixelSize(0, tabTextSize);
tabTextColor=a.getColor(0, tabTextColor);
a.recycle();
a=context.obtainStyledAttributes(attrs, R.styleable.TabStrip);
indicatorColor=a.getColor(R.styleable.TabStrip_indicatorLineColor, indicatorColor);
underlineColor=a.getColor(R.styleable.TabStrip_underlineColor, underlineColor);
tabCheckTextColor=a.getColor(R.styleable.TabStrip_tabCheckTextColor, tabTextColor);
tabTextSize=a.getDimensionPixelSize(R.styleable.TabStrip_tabTextSize, tabTextSize);
indicatorHeight=a.getDimensionPixelSize(R.styleable.TabStrip_indicatorHeight, indicatorHeight);
underlineHeight=a.getDimensionPixelSize(R.styleable.TabStrip_underlineHeight, underlineHeight);
tabPadding=a.getDimensionPixelSize(R.styleable.TabStrip_tabPaddingLeftRight, tabPadding);
shouldExpand=a.getBoolean(R.styleable.TabStrip_shouldExpand, shouldExpand);
scrollOffset=a.getDimensionPixelSize(R.styleable.TabStrip_scrollOffset, scrollOffset);
a.recycle();
rectPaint=new Paint();
rectPaint.setAntiAlias(true);
rectPaint.setStyle(Paint.Style.FILL);
defaultTabLayoutParams=new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
expandedTabLayoutParams=new LinearLayout.LayoutParams(0, LayoutParams.MATCH_PARENT, 1.0f);
if (locale==null) {
locale=getResources().getConfiguration().locale;
}
}
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();
}
public void setOnPageChangeListener(OnPageChangeListener listener) {
this.delegatePageListener=listener;
}
public void notifyDataSetChanged() {
tabsContainer.removeAllViews();
tabCount=pager.getAdapter().getCount();
for (int i=0; i < tabCount; i++) {
if (pager.getAdapter() instanceof IconTabProvider) {
addIconTab(i, ((IconTabProvider) pager.getAdapter()).getPageIconResId(i));
} else {
addTextTab(i, pager.getAdapter().getPageTitle(i).toString());
}
}
updateTabStyles();
getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
getViewTreeObserver().removeGlobalOnLayoutListener(this);
} else {
getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
currentPosition=pager.getCurrentItem();
scrollToChild(currentPosition, 0);
}
});
}
private void addTextTab(final int position, String title) {
TextView tab=new TextView(getContext());
tab.setText(title);
tab.setGravity(Gravity.CENTER);
tab.setSingleLine();
addTab(position, tab);
}
private void addIconTab(final int position, int resId) {
ImageButton tab=new ImageButton(getContext());
tab.setImageResource(resId);
addTab(position, tab);
}
private void addTab(final int position, View tab) {
tab.setFocusable(true);
tab.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
pager.setCurrentItem(position);
}
});
tab.setPadding(tabPadding, 0, tabPadding, 0);
tabsContainer.addView(tab, position, shouldExpand ? expandedTabLayoutParams : defaultTabLayoutParams);
}
private void updateTabStyles() {
for (int i=0; i < tabCount; i++) {
View v=tabsContainer.getChildAt(i);
if (v instanceof TextView) {
TextView tab=(TextView) v;
tab.setTextSize(TypedValue.COMPLEX_UNIT_PX, tabTextSize);
tab.setTypeface(tabTypeface, tabTypefaceStyle);
if (i==currentPosition){
tab.setTextColor(tabCheckTextColor);
}else {
tab.setTextColor(tabTextColor);
}
if (Build.VERSION.SDK_INT >=Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
tab.setAllCaps(true);
} else {
tab.setText(tab.getText().toString().toUpperCase(locale));
}
}
}
}
private void scrollToChild(int position, int offset) {
if (tabCount==0) {
return;
}
int newScrollX=tabsContainer.getChildAt(position).getLeft() + offset;
if (position > 0 || offset > 0) {
newScrollX -=scrollOffset;
}
if (newScrollX !=lastScrollX) {
lastScrollX=newScrollX;
scrollTo(newScrollX, 0);
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (isInEditMode() || tabCount==0) {
return;
}
final int height=getHeight();
rectPaint.setColor(indicatorColor);
View currentTab=tabsContainer.getChildAt(currentPosition);
float lineLeft=currentTab.getLeft();
float lineRight=currentTab.getRight();
if (currentPositionOffset > 0f && currentPosition < tabCount - 1) {
View nextTab=tabsContainer.getChildAt(currentPosition + 1);
final float nextTabLeft=nextTab.getLeft();
final float nextTabRight=nextTab.getRight();
lineLeft=(currentPositionOffset * nextTabLeft + (1f - currentPositionOffset) * lineLeft);
lineRight=(currentPositionOffset * nextTabRight + (1f - currentPositionOffset) * lineRight);
}
canvas.drawRect(lineLeft, height - indicatorHeight, lineRight, height, rectPaint);
// rectPaint.setColor(underlineColor);
// canvas.drawRect(0, height - underlineHeight, tabsContainer.getWidth(), height, rectPaint);
}
private class PageListener implements OnPageChangeListener {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
currentPosition=position;
currentPositionOffset=positionOffset;
updateTabStyles();
scrollToChild(position, (int) (positionOffset * tabsContainer.getChildAt(position).getWidth()));
invalidate();
if (delegatePageListener !=null) {
delegatePageListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
}
}
@Override
public void onPageScrollStateChanged(int state) {
if (state==ViewPager.SCROLL_STATE_IDLE) {
scrollToChild(pager.getCurrentItem(), 0);
}
if (delegatePageListener !=null) {
delegatePageListener.onPageScrollStateChanged(state);
}
}
@Override
public void onPageSelected(int position) {
if (delegatePageListener !=null) {
delegatePageListener.onPageSelected(position);
}
}
}
@Override
public void onRestoreInstanceState(Parcelable state) {
SavedState savedState=(SavedState) state;
super.onRestoreInstanceState(savedState.getSuperState());
currentPosition=savedState.currentPosition;
requestLayout();
}
@Override
public Parcelable onSaveInstanceState() {
Parcelable superState=super.onSaveInstanceState();
SavedState savedState=new SavedState(superState);
savedState.currentPosition=currentPosition;
return savedState;
}
static class SavedState extends BaseSavedState {
int currentPosition;
public SavedState(Parcelable superState) {
super(superState);
}
private SavedState(Parcel in) {
super(in);
currentPosition=in.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(currentPosition);
}
public static final Parcelable.Creator
@Override
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
然后在我们使用的地方只需要剪短的代码就好了。
android:id="@+id/tabstrip" android:layout_width="wrap_content" android:layout_height="match_parent" app:indicatorLineColor="@color/c9" app:indicatorHeight="3px" app:underlineColor="@color/c3" app:tabTextSize="16sp" app:tabCheckTextColor="@color/c9" app:tabPaddingLeftRight="15dp" android:scrollbars="none" /> 是不是很简单