android自定义RadioGroup可以添加多种布局的实现方法

 * 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 com.huaheng.wy.view;

import android.content.Context;import android.content.res.TypedArray;import android.util.AttributeSet;import android.view.View;import android.view.ViewGroup;import android.widget.CompoundButton;import android.widget.LinearLayout;import android.widget.RadioButton;

public class MyRadioGroup 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;

    public MyRadioGroup(Context context) {        super(context);        setOrientation(VERTICAL);        init();    }

    public MyRadioGroup(Context context, AttributeSet attrs) {        super(context, attrs);        init();    }

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

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

    @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());            }        } else if (child instanceof ViewGroup) {            final RadioButton button = findRadioButton((ViewGroup) child);            if (button.isChecked()) {                mProtectFromCheckedChange = true;                if (mCheckedId != -1) {                    setCheckedStateForView(mCheckedId, false);                }                mProtectFromCheckedChange = false;                setCheckedId(button.getId());            }        }

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

    * 查找radioButton控件 */    public RadioButton findRadioButton(ViewGroup group) {        RadioButton resBtn = null;        int len = group.getChildCount();        for (int i = 0; i < len; i++) {            if (group.getChildAt(i) instanceof RadioButton) {                resBtn = (RadioButton) group.getChildAt(i);            } else if (group.getChildAt(i) instanceof ViewGroup) {                findRadioButton((ViewGroup) group.getChildAt(i));            }        }        return resBtn;    }

    *     * <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 MyRadioGroup.LayoutParams(getContext(), attrs);    }

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

        public void onChildViewAdded(View parent, View child) {            if (parent == MyRadioGroup.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)                        .setOnCheckedChangeListener(mChildOnCheckedChangeListener);            } else if (parent == MyRadioGroup.this                    && child instanceof ViewGroup) {                RadioButton btn = findRadioButton((ViewGroup) child);                int id = btn.getId();                // generates an id if it's missing                if (id == View.NO_ID) {                    id = btn.hashCode();                    btn.setId(id);                }                btn.setOnCheckedChangeListener(mChildOnCheckedChangeListener);            }

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

        public void onChildViewRemoved(View parent, View child) {            if (parent == MyRadioGroup.this && child instanceof RadioButton) {                ((RadioButton) child).setOnCheckedChangeListener(null);            } else if (parent == MyRadioGroup.this                    && child instanceof ViewGroup) {                findRadioButton((ViewGroup) child).setOnCheckedChangeListener(                        null);            }            if (mOnHierarchyChangeListener != null) {                mOnHierarchyChangeListener.onChildViewRemoved(parent, child);            }        }    }}