NoteEditText精读

src/net/micode/notes/ui/NoteEditText.java

@@ -37,17 +37,22 @@ import net.micode.notes.R;
 import java.util.HashMap;
 import java.util.Map;
 
+//NoteEditText类拓展自EditText，添加了一些特定用于笔记应用的特性
 public class NoteEditText extends EditText {
+    //日志标签，用于调试
     private static final String TAG = "NoteEditText";
+    //变量来存储当前编辑框的索引
     private int mIndex;
+    //用于跟踪删除操作前光标位置
     private int mSelectionStartBeforeDelete;
-
+    //协议模式，用于识别文本中的特殊内容
     private static final String SCHEME_TEL = "tel:" ;
     private static final String SCHEME_HTTP = "http:" ;
     private static final String SCHEME_EMAIL = "mailto:" ;
-
+    //协议模式和资源ID映射，用于创建上下文菜单项
     private static final Map<String, Integer> sSchemaActionResMap = new HashMap<String, Integer>();
     static {
+        //将电话、网页、邮箱对应的文本资源ID填充到映射
         sSchemaActionResMap.put(SCHEME_TEL, R.string.note_link_tel);
         sSchemaActionResMap.put(SCHEME_HTTP, R.string.note_link_web);
         sSchemaActionResMap.put(SCHEME_EMAIL, R.string.note_link_email);
@@ -56,6 +61,7 @@ public class NoteEditText extends EditText {
     /**
      * Call by the {@link NoteEditActivity} to delete or add edit text
      */
+    //接口，用于监听文本视图的改变事件，例如删除和输入
     public interface OnTextViewChangeListener {
         /**
          * Delete current edit text when {@link KeyEvent#KEYCODE_DEL} happens
@@ -74,33 +80,39 @@ public class NoteEditText extends EditText {
          */
         void onTextChange(int index, boolean hasText);
     }
-
+    //用于通知文本视图更改的监听器
     private OnTextViewChangeListener mOnTextViewChangeListener;
 
+    //构造函数初始化编辑框，设置索引值为0
     public NoteEditText(Context context) {
         super(context, null);
         mIndex = 0;
     }
 
+    //设置编辑框的索引值
     public void setIndex(int index) {
         mIndex = index;
     }
 
+    //设置监听器
     public void setOnTextViewChangeListener(OnTextViewChangeListener listener) {
         mOnTextViewChangeListener = listener;
     }
 
+    //另外两个构造函数允许在创建对象使用布局属性和样式
     public NoteEditText(Context context, AttributeSet attrs) {
         super(context, attrs, android.R.attr.editTextStyle);
     }
 
     public NoteEditText(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
-        // TODO Auto-generated constructor stub
+        // TODO Auto-generated constructor stub 未实现的
     }
 
+    //触摸事件的处理，主要是为了处理文本选择
     @Override
     public boolean onTouchEvent(MotionEvent event) {
+        //处理用户的触摸事件，设置了文本的选择位置
         switch (event.getAction()) {
             case MotionEvent.ACTION_DOWN:
 
@@ -121,6 +133,7 @@ public class NoteEditText extends EditText {
         return super.onTouchEvent(event);
     }
 
+    //键盘按键事件的处理，主要是监听删除键和回车键
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
         switch (keyCode) {
@@ -138,6 +151,7 @@ public class NoteEditText extends EditText {
         return super.onKeyDown(keyCode, event);
     }
 
+    //松开按键事件的处理
     @Override
     public boolean onKeyUp(int keyCode, KeyEvent event) {
         switch(keyCode) {
@@ -167,6 +181,7 @@ public class NoteEditText extends EditText {
         return super.onKeyUp(keyCode, event);
     }
 
+    //当编辑框焦点改变时，比如失去或者获取焦点时的处理
     @Override
     protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
         if (mOnTextViewChangeListener != null) {
@@ -179,6 +194,7 @@ public class NoteEditText extends EditText {
         super.onFocusChanged(focused, direction, previouslyFocusedRect);
     }
 
+    //上下文菜单创建时的处理，可以在编辑框中添加特定行为的菜单项，例如打电话、打开网页或发送邮箱
     @Override
     protected void onCreateContextMenu(ContextMenu menu) {
         if (getText() instanceof Spanned) {