Develop Reference

Where to call bind and unbind method in custom view when using ButterKnife?

I'm new to Android. I wrote a custom view, but I just don't know where to call the bind and unbind method. I have searched for this documentation. And it seemingly suggests to use bind in the onFinishInflate() callback. But I bind the view in its constructor function and there is no crash any way. Is it correct? And how about the unbind? I find this question, it suggests to use unbind in the onDetachedFromWindow() callback. Is it required or necessary?
public class BloodIndicatorView extends FrameLayout {
#Bind(R.id.ll_record_bloodpress)
LinearLayout llRecordBloodpress;
#Bind(R.id.ll_record_bloodsugar)
LinearLayout llRecordBloodsugar;
private Context mContext;
public BloodIndicatorView(Context context) {
this(context, null);
}
public BloodIndicatorView(Context context, AttributeSet attrs) {
this(context, attrs, -1);
}
public BloodIndicatorView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
mContext = context;
init();
}
private void init() {
LayoutInflater.from(mContext).inflate(R.layout.health_blood_indicator, this);
ButterKnife.bind(this);
}
public void update() {
}
#OnClick(R.id.ll_record_bloodpress)
public void recordBloodpress() {
Intent intent = BloodPressActivity.getIntent2Act(mContext);
mContext.startActivity(intent);
}
#OnClick(R.id.ll_record_bloodsugar)
public void recordBloodsugar() {
Intent intent = BloodSugarActivity.getIntent2Act(mContext);
mContext.startActivity(intent);
}
}

You can annotate the view inside the class which you are doing correctly and since there is no error that means ButterKnife.bind(this); is happening correctly. And its not necessary to unbind this should work completely fine.

Android: PreferenceFragment with custom Preference lifecycle inconsistency?

I'm trying to create a custom Preference to be shown in PreferenceFragment as described here: Building a Custom Preference. My custom Preference should look and function as SwitchPreference, but have one additional TextView for error reporting.
I got everything implemented and UI looks fine, but I can't initialize this Preference when my PreferenceFragment is shown!
Documentation for Preference.onBindView() states that:
This is a good place to grab references to custom Views in the layout
and set properties on them.
So I did:
#Override
protected void onBindView(View view) {
super.onBindView(view);
txtError = (TextView) view.findViewById(R.id.error);
}
public void setError(String errorMessage) {
txtError.setText(errorMessage);
notifyChanged();
}
However, when I call CustomSwitchPreference.setError(String) in PreferenceFragment.onResume(), I get NPE because txtError is null.
I tried to find some workaround, but it looks like there is no lifecycle method in PreferenceFragment which is guaranteed to be called AFTER all the underlying Preferences had their Views initialized (I checked both Preference.onBindView(View) and Preference.onCreateView(ViewGroup)).
This behavior doesn't make any sense - there should be some way to initialize UIs of the underlying Preferences when PreferenceFragment is shown. How can I achieve this?
Note: calls to customPreference.setTitle(String) and customPreference.setSummary(String() in CustomPreferenceFragment.onResume() work fine. It is just the additional TextView which I can't grab a reference to...
CustomSwitchPreference.java:
public class CustomSwitchPreference extends SwitchPreference {
private TextView txtError;
public CustomSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
public CustomSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public CustomSwitchPreference(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomSwitchPreference(Context context) {
super(context);
}
#Override
protected View onCreateView(ViewGroup parent) {
setLayoutResource(R.layout.custom_switch_preference_layout);
return super.onCreateView(parent);
}
#Override
protected void onBindView(View view) {
super.onBindView(view);
txtError = (TextView) view.findViewById(R.id.error);
}
public void setError(String errorMessage) {
txtError.setText(errorMessage);
notifyChanged();
}
}
CustomPreferenceFragment.java:
public class CustomPreferenceFragment extends PreferenceFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getPreferenceManager().setSharedPreferencesName(PREFERENCES_FILE_NAME);
addPreferencesFromResource(R.xml.application_settings);
}
#Override
public void onResume() {
super.onResume();
Preference preference = findPreference("CUSTOM_PREF");
if (preference == null ||
!CustomSwitchPreference.class.isAssignableFrom(preference.getClass()))
throw new RuntimeException("couldn't get a valid reference to custom preference");
CustomSwitchPreference customPreference = (CustomSwitchPreference) preference;
customPreference.setError("error");
}
}
custom_switch_preference_layout.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_centerVertical="true"
android:layout_alignParentStart="true"
android:layout_toStartOf="#android:id/widget_frame">
<TextView
android:id="#android:id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lines="1"/>
<TextView
android:id="#android:id/summary"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxLines="3"/>
<TextView
android:id="#+id/error"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:maxLines="3"/>
</LinearLayout>
<FrameLayout
android:id="#android:id/widget_frame"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
application_settings.xml:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<com.example.settings.CustomSwitchPreference
android:key="CUSTOM_PREF"/>
</PreferenceScreen>

I couldn't find a proper solution for this issue - this inconsistency feels like a life-cycle bug in AOSP, but I'm not 100% sure about this.
As a workaround, I defined a callback interface that CustomSwitchPreference invokes in onBindView method in order to notify the containing PreferenceFragment that it had been initialized:
#Override
protected void onBindView(View view) {
super.onBindView(view);
txtError = (TextView) view.findViewById(R.id.error);
initializationListener.onInitialized(CustomSwitchPreference.this);
}
and all the manipulations on this CustomSwitchPreference that I wanted to perform in onResume now get performed in onInitialized callback. This is an ugly workaround that requires a considerable amount of boilerplate, but it seems to work.

android: calling a method each time a button is clicked

i would like to create a class, which extends Button and implement a method, which is alwasy called, when the Button is clicked. But i still want it's OnClickListener to be called.
My Idea is to save the OnClickListener into a private member when the constructor or setOnClickListener is called and then set the OnClickListener to my own OnClickListener. This one would then call my method and the saved OnClickListener.
But i don't see how i can get the OnClickListenr, i only see, how to set it.
Is there a way to acces it?
Or do you have a better idea? (it doesn't matter wheter my method is called before or after the OnClickListener)

I guess you could do this:
public class OnceClickedTwiceRunButton extends Button{
public OnceClickedTwiceRunButton(Context context) {
super(context);
}
public OnceClickedTwiceRunButton(Context context, AttributeSet attrs) {
super(context, attrs);
}
public OnceClickedTwiceRunButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
private OnClickListener extraClickMethod;
#Override
public void setOnClickListener(OnClickListener newListener)
{
super.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
DefaultClickMethod(v);
if(extraClickMethod != null)
{
extraClickMethod.onClick(v);
}
}
});
extraClickMethod = newListener;
}
private void DefaultClickMethod(View v)
{
//TODO
}
}

TextView - setCustomSelectionActionModeCallback how create ActionMode.Callback for when the text is selected to many TextView

I have several TextView in my systems and most of them I have to call my custom ActionMode.Callback.
The question is how do I create a TextView with custom ActionMode.Callback?
today my code is that way
mTxOne.setCustomSelectionActionModeCallback(new MarkTextSelectionActionModeCallback());
mTxTwo.setCustomSelectionActionModeCallback(new MarkTextSelectionActionModeCallback());
...

public class TextViewA extends TextView {
#Override
protected void onCreateContextMenu(ContextMenu menu) {
super.onCreateContextMenu(menu);
setCustomSelectionActionModeCallback(new MarkTextSelectionActionModeCallback());
}
public TextViewA(Context context) {
super(context);
}
public TextViewA(Context context,AttributeSet attrs) {
super(context,attrs);
}
public TextViewA(Context context, AttributeSet attrs, int defStyle){
super(context, attrs, defStyle);
}
Here the xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<br.com.vrbsm.textviewexample.TextViewA
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textIsSelectable="true"
android:textSize="12dp"
/>
</RelativeLayout>
here main
public class MainActivity extends Activity{
//
private TextViewA textview;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
textview = (TextViewA)findViewById(R.id.textView2);
textview.setText("Android is crazy");
}
public class MarkTextSelectionActionModeCallback implements Callback {
.
.
.}

Try this:
public class CustomActionModeTextView extends TextView{
//...implement your constructors as you may want to use...//
#Override
public ActionMode.Callback getCustomSelectionActionModeCallback (){
return new MarkTextSelectionActionModeCallback();
}
}
Create your own TextView and override the method getCustomSelectionActioModeCallback to return always an instance of your custom action mode callback. This way you don't have to set it everytime in your views.
Remember
Use your custom class in your XML layout files;
When casting it, do the cast to your custom class and not TextView;
You may wanna consider keeping a reference to your custom callback in your class. You could initialize it during some constructor and return it in the get method. This would be just to avoid creating new instances on every method call.

Creating custom control with overriding onclick

I am working on an android app and I have a custom GUI component which extends a TextView.
I want to have my custom control do a task when clicked from my custom control class and my overridden onclick method.
For example my class that extends the TextView implements the OnClick listener and writes a log to the log cat.
Then in my activity, I set an onclick listener to my custom control, and this shows a toast notification.
What I want to happen, is when my custom control is clicked, my activities overridden onclick shows the toast and the custom control class on click method also is run to show the log. But I can only seem to get one working or the other, for example, if I don't run myCustom.setOnClickListener(myListener) then the classes onclick is used and does the log, if I set the onClick listener then I only get the toast not the log.
Below is my custom control class
public class NavTextView extends TextView implements View.OnClickListener
{
public NavTextView(Context context) {
super(context);
setOnClickListener(this);
}
public NavTextView(Context context, AttributeSet attrs) {
super(context, attrs);
setOnClickListener(this);
}
public NavTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
setOnClickListener(this);
}
public NavTextView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
setOnClickListener(this);
}
#Override
public void onClick(View v) {
Log.d("NavTextView", "This has been clicked");
}
}
Below is my activities onCreate method
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
navTextView = (NavTextView)findViewById(R.id.navTextView);
navTextView.setOnClickListener(mClickListener);
}
Hope this makes sense

A View can only have one OnClickListener. In your NavTextView you are setting it there. If you later call setOnClickListener again, you are replacing the previous listener.
What you can do is override setOnClickListener in your custom View, then wrap the OnClickListener and call both.
public class MyTextView extends TextView implements View.OnClickListener
{
OnClickListener _wrappedOnClickListener;
public MyTextView(Context context) {
super(context);
super.setOnClickListener(this);
}
#Override
public void onClick(View view) {
Log.d("NavTextView", "This has been clicked");
if (_wrappedOnClickListener != null)
_wrappedOnClickListener.onClick(view);
}
#Override
public void setOnClickListener(OnClickListener l) {
_wrappedOnClickListener = l;
}
}