Android自定义支持多层嵌套RadioButton的RadioGroup

Android原生自带的RadioGroup不支持嵌套RadioButton（从源码可看出仅仅是判断子控件是不是RadioButton），参考RadioGroup自定义一个支持嵌套CompoundButton的控件XRadioGroup。

自定义XRadioGroup

public class XRadioGroup 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 XRadioGroup(Context context) {
        super(context);
        init();
    }

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

    public XRadioGroup(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public XRadioGroup(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        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);
        }
    }

    private void setViewState(View child) {
        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) {
            ViewGroup view = (ViewGroup) child;
            for (int i = 0; i < view.getChildCount(); i++) {
                setViewState(view.getChildAt(i));
            }
        }
    }

    @Override
    public void addView(View child, int index, ViewGroup.LayoutParams params) {
        setViewState(child);
        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(@IdRes 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(@IdRes 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
     * @attr ref android.R.styleable#RadioGroup_checkedButton
     * @see #check(int)
     * @see #clearCheck()
     */
    @IdRes
    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 LayoutParams(getContext(), attrs);
    }

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

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

    @Override
    public CharSequence getAccessibilityClassName() {
        return XRadioGroup.class.getName();
    }

    /**
     * <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/>
     * <p>See
     * {@link  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 ViewGroup.LayoutParams#WRAP_CONTENT} and the child's
         * height to  {@link 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(XRadioGroup group, @IdRes 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
            OnHierarchyChangeListener {
        private OnHierarchyChangeListener mOnHierarchyChangeListener;

        /**
         * {@inheritDoc}
         */
        public void onChildViewAdded(View parent, View child) {
            setListener(child);

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

        /**
         * {@inheritDoc}
         */
        public void onChildViewRemoved(View parent, View child) {
            removeListener(child);

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

    /**
     * 设置监听
     *
     * @param child
     */
    private void setListener(View child) {
        if (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 (child instanceof ViewGroup) {
            ViewGroup view = (ViewGroup) child;
            for (int i = 0; i < view.getChildCount(); i++) {
                setListener(view.getChildAt(i));
            }
        }
    }

    /**
     * 移除监听
     *
     * @param child
     */
    private void removeListener(View child) {
        if (child instanceof RadioButton) {
            ((RadioButton) child).setOnCheckedChangeListener(null);
        } else if (child instanceof ViewGroup) {
            ViewGroup view = (ViewGroup) child;
            for (int i = 0; i < view.getChildCount(); i++) {
                removeListener(view.getChildAt(i));
            }
        }
    }
}

引用XRadioGroup

xRadioGroup.setOnCheckedChangeListener(new XRadioGroup.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(XRadioGroup group, int checkedId) {
        switch (checkedId) {
            case R.id.rb_no_check:

                break;
            case R.id.rb_pass:

                break;
            case R.id.rb_no_pass:

                break;
        }
    }
});

<me.yezhou.lib.ui_widget.layout.XRadioGroup
    android:id="@+id/x_radio_group"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    app:layout_constraintTop_toBottomOf="@id/iv_photo"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    android:paddingTop="10dp"
    android:paddingBottom="10dp"
    android:orientation="horizontal"
    >
    <android.support.constraint.ConstraintLayout
        android:id="@+id/layout_no_check"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        >
        <RadioButton
            android:id="@+id/rb_no_check"
            android:layout_width="25dp"
            android:layout_height="25dp"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            android:layout_marginLeft="20dp"
            android:button="@null"
            android:background="@drawable/bg_checkbox"
            android:checked="true"
            />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:layout_constraintLeft_toRightOf="@id/rb_no_check"
            app:layout_constraintTop_toTopOf="@id/rb_no_check"
            app:layout_constraintBottom_toBottomOf="@id/rb_no_check"
            android:layout_marginLeft="5dp"
            android:text="未选择"
            />
    </android.support.constraint.ConstraintLayout>
    <android.support.constraint.ConstraintLayout
        android:id="@+id/layout_pass"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        >
        <RadioButton
            android:id="@+id/rb_pass"
            android:layout_width="25dp"
            android:layout_height="25dp"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            android:layout_marginLeft="20dp"
            android:button="@null"
            android:background="@drawable/bg_checkbox"
            />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:layout_constraintLeft_toRightOf="@id/rb_pass"
            app:layout_constraintTop_toTopOf="@id/rb_pass"
            app:layout_constraintBottom_toBottomOf="@id/rb_pass"
            android:layout_marginLeft="5dp"
            android:text="通过"
            />
    </android.support.constraint.ConstraintLayout>
    <android.support.constraint.ConstraintLayout
        android:id="@+id/layout_no_pass"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        >
        <RadioButton
            android:id="@+id/rb_no_pass"
            android:layout_width="25dp"
            android:layout_height="25dp"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            android:layout_marginLeft="20dp"
            android:button="@null"
            android:background="@drawable/bg_checkbox"
            />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:layout_constraintLeft_toRightOf="@id/rb_no_pass"
            app:layout_constraintTop_toTopOf="@id/rb_no_pass"
            app:layout_constraintBottom_toBottomOf="@id/rb_no_pass"
            android:layout_marginLeft="5dp"
            android:text="未选择"
            />
    </android.support.constraint.ConstraintLayout>
</me.yezhou.lib.ui_widget.layout.XRadioGroup>