android custom RadioGroup can add multiple implementations of the layout
- 2020-05-17 06:26:10
- OfStack
android's own RadioGroup is inherited from LinearLayout, if the layout is not directly written radiobutton, that is, radiobutton is also wrapped with a layer of container, then grouping is not successful, because radiobutton can not be found, if you want to achieve this effect, so I looked at the source code of RadioGroup, found that the problem is addView method and custom PassThroughHierarchyChangeListener;
The following two places to start, copy the source code, and then remove the RadioGroup(Context context, AttributeSet attrs) method, I added a method, find radioButton viewGroup control radioButton
/** To find the radioButton controls */
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;
}
The implementation of addView is as follows:
@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) { // Here's the code I added
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);
}
Then modify it in the custom PassThroughHierarchyChangeListener:
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 // Here's the code I added
&& 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);
}
}
}
Having done the above steps, the following layout can follow its own meaning, and the grouping effect will not be affected
Below is my layout file demo:
<com.huaheng.wy.view.MyRadioGroup
android:id="@+id/rg"
android:layout_width="fill_parent"
android:layout_height="65dp"
android:layout_alignParentBottom="true"
android:background="@drawable/yst_i_bottom"
android:orientation="horizontal" >
<!-- Home page -->
<FrameLayout
android:id="@+id/left"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginBottom="2dp"
android:layout_marginTop="3dp"
android:layout_weight="1" >
<RadioButton
android:id="@+id/rbtn_home"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:background="@null"
android:button="@null"
android:drawableTop="@drawable/yst_i_bottomhome_selector"
android:gravity="center_horizontal"
android:text=" Home page "
android:textColor="@color/white"
android:textSize="@dimen/font_5" />
<Button
android:id="@+id/btn_home_point"
android:layout_width="21dp"
android:layout_height="20dp"
android:layout_gravity="top|right"
android:layout_marginRight="10dp"
android:layout_marginTop="0dp"
android:background="@drawable/notice_bg"
android:text="1"
android:textColor="@color/white"
android:textSize="@dimen/font_6"
android:visibility="gone" />
</FrameLayout>
<!-- history -->
<RadioButton
android:id="@+id/rbtn_his"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginBottom="2dp"
android:layout_marginTop="3dp"
android:layout_weight="1"
android:background="@null"
android:button="@null"
android:drawableTop="@drawable/yst_i_bottomhis_selector"
android:gravity="center_horizontal"
android:text=" history "
android:textColor="@color/white"
android:textSize="@dimen/font_5" />
<!-- scanning -->
<Button
android:id="@+id/rbtn_scan"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:background="@drawable/scan_selector"
android:button="@null"
android:gravity="center_horizontal|bottom"
android:paddingBottom="7dp"
android:text=" scanning "
android:textColor="@color/white"
android:textSize="@dimen/font_5" />
<RadioButton
android:id="@+id/rbtn_seek"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginBottom="2dp"
android:layout_marginTop="3dp"
android:layout_weight="1"
android:background="@null"
android:button="@null"
android:drawableTop="@drawable/yst_i_bottomseek_selector"
android:gravity="center_horizontal"
android:text=" search "
android:textColor="@color/white"
android:textSize="@dimen/font_5" />
<RadioButton
android:id="@+id/rbtn_more"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginBottom="2dp"
android:layout_marginTop="3dp"
android:layout_weight="1"
android:background="@null"
android:button="@null"
android:drawableTop="@drawable/yst_i_bottommore_selector"
android:gravity="center_horizontal"
android:text=" More and more "
android:textColor="@color/white"
android:textSize="@dimen/font_5" />
</com.huaheng.wy.view.MyRadioGroup>
All the implementation code is here, so I'm going to post the custom radioGroup code in its entirety
/*
* 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);
}
/** To find the radioButton controls */
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);
}
}
}
}