今天看到项目中有一个控件写得很美丽，据说是github上开源的控件，地址没找到，例如以下图所看到的，很常见的效果，几个tab页面来回切换：
转载请标明出处：http://blog.csdn.net/goldenfish1919/article/details/46799341
FlatTabGroup.java:
public class FlatTabGroup extends RadioGroup implements RadioGroup.OnCheckedChangeListener {
public FlatTabGroup(Context context) {
this(context, null);
}
private int mRadius;
private int mStroke;
private int mHighlightColor;
private String[] mItemString;
private float mTextSize;
private ColorStateList mTextColor;
private int[] mTabViewIds;
private OnTabCheckedListener mTabCheckedListener;
public FlatTabGroup(Context context, AttributeSet attrs) {
super(context, attrs);
setOrientation(HORIZONTAL);
setGravity(Gravity.CENTER_VERTICAL);
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.FlatTabGroup);
mHighlightColor = array.getColor(R.styleable.FlatTabGroup_tab_border_color, Color.WHITE);
mStroke = array.getDimensionPixelSize(R.styleable.FlatTabGroup_tab_border_width, 2);
mRadius = array.getDimensionPixelOffset(R.styleable.FlatTabGroup_tab_radius, 5);
mTextColor = array.getColorStateList(R.styleable.FlatTabGroup_tab_textColor);
mTextSize = array.getDimensionPixelSize(R.styleable.FlatTabGroup_tab_textSize, 14);
int id = array.getResourceId(R.styleable.FlatTabGroup_tab_items, 0);
array.recycle();
mItemString = isInEditMode() ? new String[] { "TAB A", "TAB B", "TAB C"} : context.getResources().getStringArray(id);
generateTabView(context, attrs);
super.setOnCheckedChangeListener(this);
}
private void generateTabView(Context context, AttributeSet attrs) {
if (mItemString == null) {
return;
}
mTabViewIds = new int[mItemString.length];
for (int i=0; i<mItemString.length;i++ ) {
<span style="white-space:pre"> </span>String text = mItemString[i];
RadioButton button = new RadioButton(context, attrs);
button.setGravity(Gravity.CENTER);
button.setButtonDrawable(android.R.color.transparent);
button.setText(text);
button.setTextColor(mTextColor);
button.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
button.setId(mTabViewIds[i] = generateViewIds());
LayoutParams lp = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT, 1);
if(i < mItemString.length - 1){
<span style="white-space:pre"> </span>lp.rightMargin = -1 * mStroke;
}
addView(button, lp);
}
}
public void setOnTabCheckedListener(OnTabCheckedListener listener) {
mTabCheckedListener = listener;
}
public void setSelection(int position) {
check(getChildAt(position).getId());
}
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
if (mTabCheckedListener != null) {
int checkedPosition = -1;
for (int i = 0; i < mTabViewIds.length; i++) {
if (mTabViewIds[i] == checkedId) {
checkedPosition = i;
break;
}
}
mTabCheckedListener.onChecked(this, checkedPosition);
}
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
updateChildBackground();
}
@SuppressWarnings("deprecation")
private void updateChildBackground() {
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
if (child instanceof RadioButton) {
child.setBackgroundDrawable(generateTabBackground(i, mHighlightColor));
}
}
}
private Drawable generateTabBackground(int position, int color) {//怎样用代码定义selector
StateListDrawable stateListDrawable = new StateListDrawable();
stateListDrawable.addState(new int[] {android.R.attr.state_checked}, generateDrawable(position, color));
stateListDrawable.addState(new int[] { }, generateDrawable(position, Color.TRANSPARENT));
return stateListDrawable;
}
private Drawable generateDrawable(int position, int color) {
float[] radius;
if (position == 0) {
radius = new float[] {
mRadius, mRadius,
0, 0,
0, 0,
mRadius, mRadius
};
} else if (position == getChildCount() - 1) {
radius = new float[] {
0, 0,
mRadius, mRadius,
mRadius, mRadius,
0, 0
};
} else {
radius = new float[] {
0, 0,
0, 0,
0, 0,
0, 0
};
}
GradientDrawable shape = new GradientDrawable();//怎样用代码生成圆角shape
shape.setCornerRadii(radius);
shape.setColor(color);
shape.setStroke(mStroke, mHighlightColor);
return shape;
}
private static final AtomicInteger sNextGeneratedId = new AtomicInteger(1);//怎样使用自己定义的id
/**
* Generate a value suitable for use in {@link #setId(int)}. This value will
* not collide with ID values generated at build time by aapt for R.id.
*
* @return a generated ID value
*/
public static int generateViewIds() {
for (;;) {
final int result = sNextGeneratedId.get();
// aapt-generated IDs have the high byte nonzero; clamp to the range
// under that.
int newValue = result + 1;
if (newValue > 0x00FFFFFF)
newValue = 1; // Roll over to 1, not 0.
if (sNextGeneratedId.compareAndSet(result, newValue)) {
return result;
}
}
}
public static interface OnTabCheckedListener {
public void onChecked(FlatTabGroup group, int position);
}
}
这里有几个点挺有意思：
（1）怎样用代码做selector
（2）怎样用代码生成圆角
（3）怎样使用自己定义的id
attr_flat_tab_group.xml：
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="FlatTabGroup">
<attr name="tab_items" format="reference" />
<attr name="tab_border_width" format="dimension|reference" />
<attr name="tab_border_color" format="color|reference" />
<attr name="tab_radius" format="dimension|reference" />
<attr name="tab_textColor" format="reference" />
<attr name="tab_textSize" format="dimension|reference" />
</declare-styleable>
</resources>
arrays_flat_tab_group.xml：
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="array_tabs_more_video">
<item>实时直播</item>
<item>直播预约</item>
<item>精彩回看</item>
</string-array>
</resources>引用的时候：
<com.example.view.FlatTabGroup
android:id="@+id/flat_tab_group"
android:layout_width="match_parent"
android:layout_height="50dp"
android:paddingBottom="5dp"
android:paddingTop="5dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_gravity="center_vertical"
app:tab_border_color="#cdcdcd"
app:tab_border_width="1dp"
app:tab_items="@array/array_tabs_more_video"
app:tab_radius="5dp"
app:tab_textColor="@android:color/black"
app:tab_textSize="16sp"/> FlatTabGroup tabs = (FlatTabGroup)this.findViewById(R.id.flat_tab_group);
tabs.setOnTabCheckedListener(new OnTabCheckedListener(){
@Override
public void onChecked(FlatTabGroup group, int position) {
Toast.makeText(MainActivity.this, ""+position, Toast.LENGTH_SHORT).show();
}
});
tabs.setSelection(0);