Android自定义控件之自定义ViewGroup实现标签云

实现的功能：

基本绘制流程：

1、自定义属性

<resources>

<declare-styleable name="TabsViewGroup">
<attr name="tabVerticalSpace" format="dimension" />
<attr name="tabHorizontalSpace" format="dimension" />
</declare-styleable>

</resources>

2、构造函数中获取自定义属性值

public TabsViewGroup(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray attrArray = context.obtainStyledAttributes(attrs, R.styleable.TabsViewGroup);
if (attrArray != null) {
childHorizontalSpace = attrArray.getDimensionPixelSize(R.styleable.TabsViewGroup_tabHorizontalSpace, 0);
childVerticalSpace = attrArray.getDimensionPixelSize(R.styleable.TabsViewGroup_tabHorizontalSpace, 0);
attrArray.recycle();
}
}

3、onMeasure函数测量子控件大小，然后设置当前控件大小

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);

int widthModel = MeasureSpec.getMode(widthMeasureSpec);
int heightModel = MeasureSpec.getMode(heightMeasureSpec);

//输出宽度高度以及测量模式
Log.i(TAG, "sizeWidth :" + widthSize);
switch (widthModel) {
case MeasureSpec.AT_MOST:
Log.i(TAG, "Width model AT_MOST");
break;
case MeasureSpec.EXACTLY:
Log.i(TAG, "Width model EXACTLY");
break;
case MeasureSpec.UNSPECIFIED:
Log.i(TAG, "Width model UNSPECIFIED");
break;
}

Log.i(TAG, "sizeHeight :" + heightSize);
switch (heightModel) {
case MeasureSpec.AT_MOST:
Log.i(TAG, "Height model AT_MOST");

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break;
case MeasureSpec.EXACTLY:
Log.i(TAG, "Height model EXACTLY");
break;
case MeasureSpec.UNSPECIFIED:
Log.i(TAG, "Height model UNSPECIFIED");
break;
}
//左右边距
int left = getPaddingLeft();
int top = getPaddingTop();
//记录每一行的宽度和高度
int lineWidth = 0;
int lineHeight = 0;
// 如果是warp_content情况下，记录宽和高
int containerWidth = 0;
int containerHeight = 0;
// 遍历每个子元素
for (int index = 0; index < getChildCount(); index++) {
View child = getChildAt(index);
if (child.getVisibility() == GONE) {
continue;
}
measureChild(child, widthMeasureSpec, heightMeasureSpec);
MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();

int childWidth = child.getMeasuredWidth() + params.leftMargin + params.rightMargin + childHorizontalSpace;
int childHeight = child.getMeasuredHeight() + params.topMargin + params.bottomMargin + childVerticalSpace;

if (lineWidth + childWidth > widthSize - getPaddingRight() - getPaddingLeft()) {
containerWidth = Math.max(lineWidth, childWidth);
lineWidth = childWidth;
containerHeight += lineHeight;
lineHeight = childHeight;
Rect rect = new Rect(left,
containerHeight + top,
left + childWidth - childHorizontalSpace,
containerHeight + top + child.getMeasuredHeight());
child.setTag(rect);
} else {
Rect rect = new Rect(lineWidth + left,
containerHeight + top,
lineWidth + left + childWidth - childHorizontalSpace,
containerHeight + top + child.getMeasuredHeight());
child.setTag(rect);
lineWidth += childWidth;
lineHeight = Math.max(lineHeight, childHeight);
}
}

containerWidth = Math.max(containerWidth, lineWidth) + getPaddingLeft() + getPaddingRight();
containerHeight += lineHeight + getPaddingTop() + getPaddingBottom();
containerHeight -= childVerticalSpace;
setMeasuredDimension(widthModel == MeasureSpec.EXACTLY ? widthSize : containerWidth,
heightModel == MeasureSpec.EXACTLY ? heightSize : containerHeight);
}

4、onLayout函数对所有子控件重新布局

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}
Rect location = (Rect) child.getTag();
child.layout(location.left, location.top, location.right, location.bottom);
}
}

使用方法

1、布局问自己中直接引用

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:owen="http://schemas.android.com/apk/res-auto"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
android:orientation="vertical">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp"
android:textSize="16sp"
android:text="国际足球"/>

<View
android:layout_width="wrap_content"
android:layout_height="0.1dp"
android:background="#e0e0e0"/>

<com.ownchan.tabviewgroup.view.TabsViewGroup
android:id="@+id/tabs_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dip"
owen:tabHorizontalSpace="10dp"
owen:tabVerticalSpace="10dp" />

</LinearLayout>

2、代码添加标签

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}

private void initView() {
TabsViewGroup tabsViewGroup = (TabsViewGroup) findViewById(R.id.tabs_view);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
String[] tabs = new String[]{"世预赛欧洲区",
"世预赛南美区", "五人世界杯", "意甲", "美国大联盟", "乌超", "英冠", "国际冠军杯", "巴西圣保罗州杯", "巴西杯"};
for (int i = 0; i < tabs.length; i++) {
TextView textView = new TextView(this);
textView.setText(tabs[i]);
textView.setTextColor(Color.WHITE);
textView.setBackgroundDrawable(getResources().getDrawable(R.drawable.tabs_bg));
textView.setGravity(Gravity.CENTER);
textView.setPadding(10, 0, 10, 0);
textView.setTextSize(16);
tabsViewGroup.addView(textView, params);
}
}

效果图：

项目Github地址