Builder模式在Android自定义底部对话框的实现

一、什么事Builder模式

定义：

将一个复杂对象的构建与它的表示分离，使得同样的构建过程可以创建不同的表示。

模式的使用场景：

相同的方法，不同的执行顺序，产生不同的事件结果时；

多个部件或零件，都可以装配到一个对象中，但是产生的运行结果又不相同时；

产品类非常复杂，或者产品类中的调用顺序不同产生了不同的效能，这个时候使用建造者模式非常合适；

废话不多说，上代码先

1.构建对话框类

public class NewGhostDialog {

private Context context;
private Dialog dialog;
private GridView gridView;
private ArrayList<Icon> iconList = new ArrayList<>();

public NewGhostDialog(Context context) {
this.context = context;
WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
}

/**
* 创建
* @return
*/
public NewGhostDialog builder(){
initView();
setListener();
return this;
}

private void initView(){
View view = LayoutInflater.from(context).inflate(R.layout.dialog_ghost_new, null);
// 获取自定义Dialog布局中的控件
gridView = (GridView) view.findViewById(R.id.ghostGV);
// 定义Dialog布局和参数
dialog = new Dialog(context, R.style.GhostDialogStyle);
dialog.setContentView(view);
Window dialogWindow = dialog.getWindow();
dialogWindow.setGravity(Gravity.LEFT | Gravity.BOTTOM);
WindowManager.LayoutParams lp = dialogWindow.getAttributes();
lp.x = 0;
lp.y = 0;
lp.width = WindowManager.LayoutParams.MATCH_PARENT;
//                lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
dialogWindow.setAttributes(lp);
gridView.setAdapter(new GhostAdapter());
}

/**
*
* @param picRes 图标图片
* @param name 图标名字
* @param listener 点击监听
* @return
*/
public NewGhostDialog addItem(int picRes, String name, NewGhostDialog.OnGhostItemClickListener listener) {
if (iconList == null) {
iconList = new ArrayList<>();
}
iconList.add(new Icon(picRes, name, listener));
return this;
}

/**
* 可否按返回键取消
* @param cancel
* @return
*/
public NewGhostDialog setCancelable(boolean cancel) {
dialog.setCancelable(cancel);
return this;
}

/**
* 可否按对话框外部区域取消
* @param cancel
* @return
*/
public NewGhostDialog setCanceledOnTouchOutside(boolean cancel) {
dialog.setCanceledOnTouchOutside(cancel);
return this;
}

/**
* 显示
* @return
*/
public NewGhostDialog show() {
dialog.show();
return this;
}

/**
* 设置点击监听
* @return
*/
public NewGhostDialog setListener(){
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//调用图标点击接口，顺便把图标位置传递过去
iconList.get(position).listener.onClick(position);
dialog.dismiss();
}
});
return this;
}

/**
* 图标类
*/
public class Icon{
public int iconRes;
public String info;
public NewGhostDialog.OnGhostItemClickListener listener;

public Icon(int iconRes, String info, NewGhostDialog.OnGhostItemClickListener listener) {
this.iconRes = iconRes;
this.info = info;
this.listener = listener;
}
}

private class GhostAdapter extends BaseAdapter{

@Override
public int getCount() {
return iconList.size();
}

@Override
public Icon getItem(int position) {
Icon icon = null;
if (null != iconList)
{
icon = iconList.get(position);
}
return icon;
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (null == convertView)
{
viewHolder = new ViewHolder();
LayoutInflater mInflater = LayoutInflater.from(context);
convertView = mInflater.inflate(R.layout.item_ghost_icon, null);
viewHolder.infoTV = (TextView) convertView.findViewById(R.id.infoTV);
viewHolder.iconIV = (ImageView) convertView.findViewById(R.id.iconIV);
convertView.setTag(viewHolder);
}
else
{
viewHolder = (ViewHolder) convertView.getTag();
}

Icon icon = getItem(position);
if (null != icon)
{
viewHolder.iconIV.setImageResource(icon.iconRes);
viewHolder.infoTV.setText(icon.info);
}

return convertView;
}
}

private static class ViewHolder
{
TextView infoTV;
ImageView iconIV;
}

/**
* 点击事件接口
*/
public interface OnGhostItemClickListener {
void onClick(int position);
}

}

知识点：①ViewHolder的使用优化

②接口的定义与调用

item_ghost_icon

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical"
>
<!-- item点击效果添加这个到上面 android:background="@drawable/item_background_selector"-->

<ImageView
android:id="@+id/iconIV"
android:layout_width="40dip"
android:layout_height="40dip"
android:scaleType="fitXY"
android:src="@mipmap/ic_launcher" />

<TextView
android:id="@+id/infoTV"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="2dp"
android:text="@string/app_name"
android:textColor="#000000"
android:textSize="14sp" />

</LinearLayout>

dialog_ghost_new

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"

android:background="@color/white">

<GridView
android:id="@+id/ghostGV"
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="0px"
android:layout_marginRight="0px"
android:listSelector="@android:color/transparent"
android:numColumns="3"/>

</RelativeLayout>

dialog进退场动画

<style name="GhostDialogStyle" parent="@android:style/Theme.Dialog">
<!-- 背景透明 -->
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowContentOverlay">@null</item>
<!-- 浮于Activity之上 -->
<item name="android:windowIsFloating">true</item>
<!-- 边框 -->
<item name="android:windowFrame">@null</item>
<!-- Dialog以外的区域模糊效果 -->
<item name="android:backgroundDimEnabled">true</item>
<!-- 无标题 -->
<item name="android:windowNoTitle">true</item>
<!-- 半透明 -->
<item name="android:windowIsTranslucent">true</item>
<!-- Dialog进入及退出动画 -->
<item name="android:windowAnimationStyle">@style/ActionSheetDialogAnimation</item>
</style>
<!-- GhostDialog进出动画 -->
<style name="ActionSheetDialogAnimation" parent="@android:style/Animation.Dialog">
<item name="android:windowEnterAnimation">@anim/dialog_ghost_in</item>
<item name="android:windowExitAnimation">@anim/dialog_ghost_out</item>
</style>

上面的文件就可以做为一个控件啦，调用方式

new NewGhostDialog(NWMainActivity.this).builder()
.addItem(R.mipmap.ic_launcher, "新世界", new NewGhostDialog.OnGhostItemClickListener() {
@Override
public void onClick(int position) {
UIToast.showToastShort(NWMainActivity.this, "第一个");
}
})
.addItem(R.mipmap.ic_launcher, "新地球", new NewGhostDialog.OnGhostItemClickListener() {
@Override
public void onClick(int position) {
UIToast.showToastShort(NWMainActivity.this, "第二个");
}
})
.addItem(R.mipmap.ic_launcher, "新宇宙", new NewGhostDialog.OnGhostItemClickListener() {
@Override
public void onClick(int position) {
UIToast.showToastShort(NWMainActivity.this, "第三个");
}
})
.setCanceledOnTouchOutside(true)
.setCancelable(true)
.show();