core/java/android/widget/RadioGroup.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2006 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package android.widget;

 import com.android.internal.R;

 import android.content.Context;
 import android.content.res.TypedArray;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewGroup;


 /**
  * <p>This class is used to create a multiple-exclusion scope for a set of radio
  * buttons. Checking one radio button that belongs to a radio group unchecks
  * any previously checked radio button within the same group.</p>
  *
  * <p>Intially, all of the radio buttons are unchecked. While it is not possible
  * to uncheck a particular radio button, the radio group can be cleared to
  * remove the checked state.</p>
  *
  * <p>The selection is identified by the unique id of the radio button as defined
  * in the XML layout file.</p>
  *
  * <p><strong>XML Attributes</strong></p>
  * <p>See {@link android.R.styleable#RadioGroup RadioGroup Attributes},
  * {@link android.R.styleable#LinearLayout LinearLayout Attributes},
  * {@link android.R.styleable#ViewGroup ViewGroup Attributes},
  * {@link android.R.styleable#View View Attributes}</p>
  * <p>Also see
  * {@link android.widget.LinearLayout.LayoutParams LinearLayout.LayoutParams}
  * for layout attributes.</p>
  *
  * @see RadioButton
  *
  */
 public class RadioGroup extends LinearLayout {
     // holds the checked id; the selection is empty by default
     private int mCheckedId = -1;
     // tracks children radio buttons checked state
     private CompoundButton.OnCheckedChangeListener mChildOnCheckedChangeListener;
     // when true, mOnCheckedChangeListener discards events
     private boolean mProtectFromCheckedChange = false;
     private OnCheckedChangeListener mOnCheckedChangeListener;
     private PassThroughHierarchyChangeListener mPassThroughListener;

     /**
      * {@inheritDoc}
      */
     public RadioGroup(Context context) {
         super(context);
         setOrientation(VERTICAL);
         init();
     }

     /**
      * {@inheritDoc}
      */
     public RadioGroup(Context context, AttributeSet attrs) {
         super(context, attrs);

         // retrieve selected radio button as requested by the user in the
         // XML layout file
         TypedArray attributes = context.obtainStyledAttributes(
                 attrs, com.android.internal.R.styleable.RadioGroup, com.android.internal.R.attr.radioButtonStyle, 0);

         int value = attributes.getResourceId(R.styleable.RadioGroup_checkedButton, View.NO_ID);
         if (value != View.NO_ID) {
             mCheckedId = value;
         }

         final int index = attributes.getInt(com.android.internal.R.styleable.RadioGroup_orientation, VERTICAL);
         setOrientation(index);

         attributes.recycle();
         init();
     }

     private void init() {
         mChildOnCheckedChangeListener = new CheckedStateTracker();
         mPassThroughListener = new PassThroughHierarchyChangeListener();
         super.setOnHierarchyChangeListener(mPassThroughListener);
     }

     /**
      * {@inheritDoc}
      */
     @Override
     public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
         // the user listener is delegated to our pass-through listener
         mPassThroughListener.mOnHierarchyChangeListener = listener;
     }

     /**
      * {@inheritDoc}
      */
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();

         // checks the appropriate radio button as requested in the XML file
         if (mCheckedId != -1) {
             mProtectFromCheckedChange = true;
             setCheckedStateForView(mCheckedId, true);
             mProtectFromCheckedChange = false;
             setCheckedId(mCheckedId);
         }
     }

     @Override
     public void addView(View child, int index, ViewGroup.LayoutParams params) {
         if (child instanceof RadioButton) {
             final RadioButton button = (RadioButton) child;
             if (button.isChecked()) {
                 mProtectFromCheckedChange = true;
                 if (mCheckedId != -1) {
                     setCheckedStateForView(mCheckedId, false);
                 }
                 mProtectFromCheckedChange = false;
                 setCheckedId(button.getId());
             }
         }

         super.addView(child, index, params);
     }

     /**
      * <p>Sets the selection to the radio button whose identifier is passed in
      * parameter. Using -1 as the selection identifier clears the selection;
      * such an operation is equivalent to invoking {@link #clearCheck()}.</p>
      *
      * @param id the unique id of the radio button to select in this group
      *
      * @see #getCheckedRadioButtonId()
      * @see #clearCheck()
      */
     public void check(int id) {
         // don't even bother
         if (id != -1 && (id == mCheckedId)) {
             return;
         }

         if (mCheckedId != -1) {
             setCheckedStateForView(mCheckedId, false);
         }

         if (id != -1) {
             setCheckedStateForView(id, true);
         }

         setCheckedId(id);
     }

     private void setCheckedId(int id) {
         mCheckedId = id;
         if (mOnCheckedChangeListener != null) {
             mOnCheckedChangeListener.onCheckedChanged(this, mCheckedId);
         }
     }

     private void setCheckedStateForView(int viewId, boolean checked) {
         View checkedView = findViewById(viewId);
         if (checkedView != null && checkedView instanceof RadioButton) {
             ((RadioButton) checkedView).setChecked(checked);
         }
     }

     /**
      * <p>Returns the identifier of the selected radio button in this group.
      * Upon empty selection, the returned value is -1.</p>
      *
      * @return the unique id of the selected radio button in this group
      *
      * @see #check(int)
      * @see #clearCheck()
      */
     public int getCheckedRadioButtonId() {
         return mCheckedId;
     }

     /**
      * <p>Clears the selection. When the selection is cleared, no radio button
      * in this group is selected and {@link #getCheckedRadioButtonId()} returns
      * null.</p>
      *
      * @see #check(int)
      * @see #getCheckedRadioButtonId()
      */
     public void clearCheck() {
         check(-1);
     }

     /**
      * <p>Register a callback to be invoked when the checked radio button
      * changes in this group.</p>
      *
      * @param listener the callback to call on checked state change
      */
     public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
         mOnCheckedChangeListener = listener;
     }

     /**
      * {@inheritDoc}
      */
     @Override
     public LayoutParams generateLayoutParams(AttributeSet attrs) {
         return new RadioGroup.LayoutParams(getContext(), attrs);
     }

     /**
      * {@inheritDoc}
      */
     @Override
     protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
         return p instanceof RadioGroup.LayoutParams;
     }

     @Override
     protected LinearLayout.LayoutParams generateDefaultLayoutParams() {
         return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
     }

     /**
      * <p>This set of layout parameters defaults the width and the height of
      * the children to {@link #WRAP_CONTENT} when they are not specified in the
      * XML file. Otherwise, this class ussed the value read from the XML file.</p>
      *
      * <p>See
      * {@link android.R.styleable#LinearLayout_Layout LinearLayout Attributes}
      * for a list of all child view attributes that this class supports.</p>
      *
      */
     public static class LayoutParams extends LinearLayout.LayoutParams {
         /**
          * {@inheritDoc}
          */
         public LayoutParams(Context c, AttributeSet attrs) {
             super(c, attrs);
         }

         /**
          * {@inheritDoc}
          */
         public LayoutParams(int w, int h) {
             super(w, h);
         }

         /**
          * {@inheritDoc}
          */
         public LayoutParams(int w, int h, float initWeight) {
             super(w, h, initWeight);
         }

         /**
          * {@inheritDoc}
          */
         public LayoutParams(ViewGroup.LayoutParams p) {
             super(p);
         }

         /**
          * {@inheritDoc}
          */
         public LayoutParams(MarginLayoutParams source) {
             super(source);
         }

         /**
          * <p>Fixes the child's width to
          * {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT} and the child's
          * height to  {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}
          * when not specified in the XML file.</p>
          *
          * @param a the styled attributes set
          * @param widthAttr the width attribute to fetch
          * @param heightAttr the height attribute to fetch
          */
         @Override
         protected void setBaseAttributes(TypedArray a,
                 int widthAttr, int heightAttr) {

             if (a.hasValue(widthAttr)) {
                 width = a.getLayoutDimension(widthAttr, "layout_width");
             } else {
                 width = WRAP_CONTENT;
             }

             if (a.hasValue(heightAttr)) {
                 height = a.getLayoutDimension(heightAttr, "layout_height");
             } else {
                 height = WRAP_CONTENT;
             }
         }
     }

     /**
      * <p>Interface definition for a callback to be invoked when the checked
      * radio button changed in this group.</p>
      */
     public interface OnCheckedChangeListener {
         /**
          * <p>Called when the checked radio button has changed. When the
          * selection is cleared, checkedId is -1.</p>
          *
          * @param group the group in which the checked radio button has changed
          * @param checkedId the unique identifier of the newly checked radio button
          */
         public void onCheckedChanged(RadioGroup group, int checkedId);
     }

     private class CheckedStateTracker implements CompoundButton.OnCheckedChangeListener {
         public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
             // prevents from infinite recursion
             if (mProtectFromCheckedChange) {
                 return;
             }

             mProtectFromCheckedChange = true;
             if (mCheckedId != -1) {
                 setCheckedStateForView(mCheckedId, false);
             }
             mProtectFromCheckedChange = false;

             int id = buttonView.getId();
             setCheckedId(id);
         }
     }

     /**
      * <p>A pass-through listener acts upon the events and dispatches them
      * to another listener. This allows the table layout to set its own internal
      * hierarchy change listener without preventing the user to setup his.</p>
      */
     private class PassThroughHierarchyChangeListener implements
             ViewGroup.OnHierarchyChangeListener {
         private ViewGroup.OnHierarchyChangeListener mOnHierarchyChangeListener;

         /**
          * {@inheritDoc}
          */
         public void onChildViewAdded(View parent, View child) {
             if (parent == RadioGroup.this && child instanceof RadioButton) {
                 int id = child.getId();
                 // generates an id if it's missing
                 if (id == View.NO_ID) {
                     id = child.hashCode();
                     child.setId(id);
                 }
                 ((RadioButton) child).setOnCheckedChangeWidgetListener(
                         mChildOnCheckedChangeListener);
             }

             if (mOnHierarchyChangeListener != null) {
                 mOnHierarchyChangeListener.onChildViewAdded(parent, child);
             }
         }

         /**
          * {@inheritDoc}
          */
         public void onChildViewRemoved(View parent, View child) {
             if (parent == RadioGroup.this && child instanceof RadioButton) {
                 ((RadioButton) child).setOnCheckedChangeWidgetListener(null);
             }

             if (mOnHierarchyChangeListener != null) {
                 mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
             }
         }
     }
 }
	/*
	* Copyright (C) 2006 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package android.widget;

	import com.android.internal.R;

	import android.content.Context;
	import android.content.res.TypedArray;
	import android.util.AttributeSet;
	import android.view.View;
	import android.view.ViewGroup;


	/**
	* <p>This class is used to create a multiple-exclusion scope for a set of radio
	* buttons. Checking one radio button that belongs to a radio group unchecks
	* any previously checked radio button within the same group.</p>
	*
	* <p>Intially, all of the radio buttons are unchecked. While it is not possible
	* to uncheck a particular radio button, the radio group can be cleared to
	* remove the checked state.</p>
	*
	* <p>The selection is identified by the unique id of the radio button as defined
	* in the XML layout file.</p>
	*
	* <p><strong>XML Attributes</strong></p>
	* <p>See {@link android.R.styleable#RadioGroup RadioGroup Attributes},
	* {@link android.R.styleable#LinearLayout LinearLayout Attributes},
	* {@link android.R.styleable#ViewGroup ViewGroup Attributes},
	* {@link android.R.styleable#View View Attributes}</p>
	* <p>Also see
	* {@link android.widget.LinearLayout.LayoutParams LinearLayout.LayoutParams}
	* for layout attributes.</p>
	*
	* @see RadioButton
	*
	*/
	public class RadioGroup extends LinearLayout {
	// holds the checked id; the selection is empty by default
	private int mCheckedId = -1;
	// tracks children radio buttons checked state
	private CompoundButton.OnCheckedChangeListener mChildOnCheckedChangeListener;
	// when true, mOnCheckedChangeListener discards events
	private boolean mProtectFromCheckedChange = false;
	private OnCheckedChangeListener mOnCheckedChangeListener;
	private PassThroughHierarchyChangeListener mPassThroughListener;

	/**
	* {@inheritDoc}
	*/
	public RadioGroup(Context context) {
	super(context);
	setOrientation(VERTICAL);
	init();
	}

	/**
	* {@inheritDoc}
	*/
	public RadioGroup(Context context, AttributeSet attrs) {
	super(context, attrs);

	// retrieve selected radio button as requested by the user in the
	// XML layout file
	TypedArray attributes = context.obtainStyledAttributes(
	attrs, com.android.internal.R.styleable.RadioGroup, com.android.internal.R.attr.radioButtonStyle, 0);

	int value = attributes.getResourceId(R.styleable.RadioGroup_checkedButton, View.NO_ID);
	if (value != View.NO_ID) {
	mCheckedId = value;
	}

	final int index = attributes.getInt(com.android.internal.R.styleable.RadioGroup_orientation, VERTICAL);
	setOrientation(index);

	attributes.recycle();
	init();
	}

	private void init() {
	mChildOnCheckedChangeListener = new CheckedStateTracker();
	mPassThroughListener = new PassThroughHierarchyChangeListener();
	super.setOnHierarchyChangeListener(mPassThroughListener);
	}

	/**
	* {@inheritDoc}
	*/
	@Override
	public void setOnHierarchyChangeListener(OnHierarchyChangeListener listener) {
	// the user listener is delegated to our pass-through listener
	mPassThroughListener.mOnHierarchyChangeListener = listener;
	}

	/**
	* {@inheritDoc}
	*/
	@Override
	protected void onFinishInflate() {
	super.onFinishInflate();

	// checks the appropriate radio button as requested in the XML file
	if (mCheckedId != -1) {
	mProtectFromCheckedChange = true;
	setCheckedStateForView(mCheckedId, true);
	mProtectFromCheckedChange = false;
	setCheckedId(mCheckedId);
	}
	}

	@Override
	public void addView(View child, int index, ViewGroup.LayoutParams params) {
	if (child instanceof RadioButton) {
	final RadioButton button = (RadioButton) child;
	if (button.isChecked()) {
	mProtectFromCheckedChange = true;
	if (mCheckedId != -1) {
	setCheckedStateForView(mCheckedId, false);
	}
	mProtectFromCheckedChange = false;
	setCheckedId(button.getId());
	}
	}

	super.addView(child, index, params);
	}

	/**
	* <p>Sets the selection to the radio button whose identifier is passed in
	* parameter. Using -1 as the selection identifier clears the selection;
	* such an operation is equivalent to invoking {@link #clearCheck()}.</p>
	*
	* @param id the unique id of the radio button to select in this group
	*
	* @see #getCheckedRadioButtonId()
	* @see #clearCheck()
	*/
	public void check(int id) {
	// don't even bother
	if (id != -1 && (id == mCheckedId)) {
	return;
	}

	if (mCheckedId != -1) {
	setCheckedStateForView(mCheckedId, false);
	}

	if (id != -1) {
	setCheckedStateForView(id, true);
	}

	setCheckedId(id);
	}

	private void setCheckedId(int id) {
	mCheckedId = id;
	if (mOnCheckedChangeListener != null) {
	mOnCheckedChangeListener.onCheckedChanged(this, mCheckedId);
	}
	}

	private void setCheckedStateForView(int viewId, boolean checked) {
	View checkedView = findViewById(viewId);
	if (checkedView != null && checkedView instanceof RadioButton) {
	((RadioButton) checkedView).setChecked(checked);
	}
	}

	/**
	* <p>Returns the identifier of the selected radio button in this group.
	* Upon empty selection, the returned value is -1.</p>
	*
	* @return the unique id of the selected radio button in this group
	*
	* @see #check(int)
	* @see #clearCheck()
	*/
	public int getCheckedRadioButtonId() {
	return mCheckedId;
	}

	/**
	* <p>Clears the selection. When the selection is cleared, no radio button
	* in this group is selected and {@link #getCheckedRadioButtonId()} returns
	* null.</p>
	*
	* @see #check(int)
	* @see #getCheckedRadioButtonId()
	*/
	public void clearCheck() {
	check(-1);
	}

	/**
	* <p>Register a callback to be invoked when the checked radio button
	* changes in this group.</p>
	*
	* @param listener the callback to call on checked state change
	*/
	public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
	mOnCheckedChangeListener = listener;
	}

	/**
	* {@inheritDoc}
	*/
	@Override
	public LayoutParams generateLayoutParams(AttributeSet attrs) {
	return new RadioGroup.LayoutParams(getContext(), attrs);
	}

	/**
	* {@inheritDoc}
	*/
	@Override
	protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
	return p instanceof RadioGroup.LayoutParams;
	}

	@Override
	protected LinearLayout.LayoutParams generateDefaultLayoutParams() {
	return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
	}

	/**
	* <p>This set of layout parameters defaults the width and the height of
	* the children to {@link #WRAP_CONTENT} when they are not specified in the
	* XML file. Otherwise, this class ussed the value read from the XML file.</p>
	*
	* <p>See
	* {@link android.R.styleable#LinearLayout_Layout LinearLayout Attributes}
	* for a list of all child view attributes that this class supports.</p>
	*
	*/
	public static class LayoutParams extends LinearLayout.LayoutParams {
	/**
	* {@inheritDoc}
	*/
	public LayoutParams(Context c, AttributeSet attrs) {
	super(c, attrs);
	}

	/**
	* {@inheritDoc}
	*/
	public LayoutParams(int w, int h) {
	super(w, h);
	}

	/**
	* {@inheritDoc}
	*/
	public LayoutParams(int w, int h, float initWeight) {
	super(w, h, initWeight);
	}

	/**
	* {@inheritDoc}
	*/
	public LayoutParams(ViewGroup.LayoutParams p) {
	super(p);
	}

	/**
	* {@inheritDoc}
	*/
	public LayoutParams(MarginLayoutParams source) {
	super(source);
	}

	/**
	* <p>Fixes the child's width to
	* {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT} and the child's
	* height to {@link android.view.ViewGroup.LayoutParams#WRAP_CONTENT}
	* when not specified in the XML file.</p>
	*
	* @param a the styled attributes set
	* @param widthAttr the width attribute to fetch
	* @param heightAttr the height attribute to fetch
	*/
	@Override
	protected void setBaseAttributes(TypedArray a,
	int widthAttr, int heightAttr) {

	if (a.hasValue(widthAttr)) {
	width = a.getLayoutDimension(widthAttr, "layout_width");
	} else {
	width = WRAP_CONTENT;
	}

	if (a.hasValue(heightAttr)) {
	height = a.getLayoutDimension(heightAttr, "layout_height");
	} else {
	height = WRAP_CONTENT;
	}
	}
	}

	/**
	* <p>Interface definition for a callback to be invoked when the checked
	* radio button changed in this group.</p>
	*/
	public interface OnCheckedChangeListener {
	/**
	* <p>Called when the checked radio button has changed. When the
	* selection is cleared, checkedId is -1.</p>
	*
	* @param group the group in which the checked radio button has changed
	* @param checkedId the unique identifier of the newly checked radio button
	*/
	public void onCheckedChanged(RadioGroup group, int checkedId);
	}

	private class CheckedStateTracker implements CompoundButton.OnCheckedChangeListener {
	public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
	// prevents from infinite recursion
	if (mProtectFromCheckedChange) {
	return;
	}

	mProtectFromCheckedChange = true;
	if (mCheckedId != -1) {
	setCheckedStateForView(mCheckedId, false);
	}
	mProtectFromCheckedChange = false;

	int id = buttonView.getId();
	setCheckedId(id);
	}
	}

	/**
	* <p>A pass-through listener acts upon the events and dispatches them
	* to another listener. This allows the table layout to set its own internal
	* hierarchy change listener without preventing the user to setup his.</p>
	*/
	private class PassThroughHierarchyChangeListener implements
	ViewGroup.OnHierarchyChangeListener {
	private ViewGroup.OnHierarchyChangeListener mOnHierarchyChangeListener;

	/**
	* {@inheritDoc}
	*/
	public void onChildViewAdded(View parent, View child) {
	if (parent == RadioGroup.this && child instanceof RadioButton) {
	int id = child.getId();
	// generates an id if it's missing
	if (id == View.NO_ID) {
	id = child.hashCode();
	child.setId(id);
	}
	((RadioButton) child).setOnCheckedChangeWidgetListener(
	mChildOnCheckedChangeListener);
	}

	if (mOnHierarchyChangeListener != null) {
	mOnHierarchyChangeListener.onChildViewAdded(parent, child);
	}
	}

	/**
	* {@inheritDoc}
	*/
	public void onChildViewRemoved(View parent, View child) {
	if (parent == RadioGroup.this && child instanceof RadioButton) {
	((RadioButton) child).setOnCheckedChangeWidgetListener(null);
	}

	if (mOnHierarchyChangeListener != null) {
	mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
	}
	}
	}
	}