I want write code once and use in different activities. I have created a Base Activity class for that . Also the header of all the layouts in different activities are same. I have done that with the help of the <include layout > tag.
Now the Problem is my BaseActivity code is not running. I am trying this first time se don't have much idea about that.
1.)The BaseActivity code is below :
package com.waheguru.app;
import android.R.integer;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public abstract class BaseActivityMenu extends Activity {
//action id
private static final int ID_UP = 1;
private static final int ID_DOWN = 2;
private static final int ID_SEARCH = 3;
private static final int ID_INFO = 4;
private static final int ID_ERASE = 5;
private static final int ID_OK = 6;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.header);
ActionItem nextItem = new ActionItem(ID_DOWN, "Book", getResources().getDrawable(R.drawable.menu_down_arrow));
ActionItem prevItem = new ActionItem(ID_UP, "Bookmark", getResources().getDrawable(R.drawable.menu_up_arrow));
ActionItem searchItem = new ActionItem(ID_SEARCH, "Find", getResources().getDrawable(R.drawable.menu_search));
ActionItem infoItem = new ActionItem(ID_INFO, "Info", getResources().getDrawable(R.drawable.menu_info));
ActionItem eraseItem = new ActionItem(ID_ERASE, "Clear", getResources().getDrawable(R.drawable.menu_eraser));
ActionItem okItem = new ActionItem(ID_OK, "OK", getResources().getDrawable(R.drawable.menu_ok));
//use setSticky(true) to disable QuickAction dialog being dismissed after an item is clicked
prevItem.setSticky(true);
nextItem.setSticky(true);
//create QuickAction. Use QuickAction.VERTICAL or QuickAction.HORIZONTAL param to define layout
//orientation
final QuickAction quickAction = new QuickAction(this, QuickAction.VERTICAL);
//add action items into QuickAction
quickAction.addActionItem(nextItem);
quickAction.addActionItem(prevItem);
quickAction.addActionItem(searchItem);
quickAction.addActionItem(infoItem);
quickAction.addActionItem(eraseItem);
quickAction.addActionItem(okItem);
//Set listener for action item clicked
quickAction.setOnActionItemClickListener(new QuickAction.OnActionItemClickListener() {
public void onItemClick(QuickAction source, int pos, int actionId) {
ActionItem actionItem = quickAction.getActionItem(pos);
//here we can filter which action item was clicked with pos or actionId parameter
if (actionId == ID_SEARCH) {
Toast.makeText(getApplicationContext(), "Let's do some search action", Toast.LENGTH_SHORT).show();
} else if (actionId == ID_INFO) {
Toast.makeText(getApplicationContext(), "I have no info this time", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), actionItem.getTitle() + " selected", Toast.LENGTH_SHORT).show();
}
}
});
//set listnener for on dismiss event, this listener will be called only if QuickAction dialog was dismissed
//by clicking the area outside the dialog.
quickAction.setOnDismissListener(new QuickAction.OnDismissListener() {
public void onDismiss() {
Toast.makeText(getApplicationContext(), "Dismissed", Toast.LENGTH_SHORT).show();
}
});
Button books=(Button)findViewById(R.id.book);
books.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent intent=new Intent(ExampleActivity.this,List_of_books.class);
startActivityForResult(intent, 0);
}
});
//show on btn1
Button btn1 = (Button) this.findViewById(R.id.menu);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
quickAction.show(v);
}
});
}
}
2.) The Activity extended the Base Activity
package com.waheguru.app;
import android.app.Activity;
import android.os.Bundle;
public class ABCActivity extends BaseActivityMenu {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
}
}
So can any one help me where I am doing something wrong.
For this you have to create one header.xml which will be included in each and every layout for your activities as follows
header.xml
<RelativeLayout>
<TextView android:id="#+id/txtHeading"
.... />
</RelativeLayout>
activity_main.xml
<RelativeLayout>
<!-- include your header here -->
<include layout="#layout/header"
... />
<!-- Rest of your views -->
</RelativeLayout>
BaseActivity
abstract class BaseActivity extends Activity {
protected TextView txtHeading;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
protected void setHeading(int resId) {
if(txtHeading == null)
txtHeading = findViewById(R.id.txtHeading);
if(txtHeading != null)
txtHeading.setText(resId);
}
}
MainActivity
class MainActivity extends BaseActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setHeading(R.string.heading_main);
}
}
You can put as many views you want and manage common things in BaseActivity or BaseListActivity.
If you are making inheritance with activities and your base activity calls setContentView and after that the real activity calls setContentView the last call will set the layout for activity. So if you are looking for a solution where all activies have the same header component the are 2 ways.
For each activity layout xml you include that component
-You make function for baseActivity e.g. setContent(int layout_id)
-You call that with your activity always.
-Baseactivity inflates a root view with header and inflates layout_id view to that layout.
-Then calls the actual setContentView with that component.
I think you should achieve it using Fragment, this may helps you.
1 - in main.xml, add:
<fragment
android:id="#+id/header"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
class="com.package.name.HeaderPanel" />
//remaining is same
2 - the BaseActivity which extends FragmentActivity:
public class BaseActivityMenu extends FragmentActivity {
private static final String TAG = Default.class.getName() + " - ";
private int mResLayoutId;
public void onCreate(Bundle savedInstanceState, int resLayout){
super.onCreate(savedInstanceState);
setContentView(resLayout);
mResLayoutId = resLayout;
switch(mResLayoutId){
// here change with your xml file
case R.layout.home:
// set here common control like header textview
break;
default:
break;
}
}
}
3 - Now, you can extend your Activity with the BaseActivity. This will allow the Activity to be extended by FragmentActivity:
public class ABCActivity extends BaseActivityMenu {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState, R.layout.home);
}
}
In code, your base activity is called ExampleActivity, but in your child class you are extending BaseActivityMenu. Don't know where its coming from.
Perhaps change:
public class ABCActivity extends BaseActivityMenu
To this:
public class ABCActivity extends ExampleActivity
Moreover, I would suggest you to define your base activity (ExampleActivity) as an Abstract class.
For example:
public abstract class ExampleActivity extends Activity
Doing so will not define your base class as concrete and will make it easier to debug in case of problems.
Related
Lets say I have a few buttons and their click is handled by a common handler is there a way to define the listener once and not defining an onClick attribute for each button?
<Button android:onClick="handler" />
Perhaps parent delegation as in browsers or some interceptor .....imagine you have 50 buttons, you declare on click for each explicitly???
Yes you can do so.
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
List<Button> buttons;
ViewGroup parentView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttons = new ArrayList<>();
parentView = (ViewGroup) findViewById(R.id.cord);
//Replace the above line with the container view i.e.
//Replace parentView = (ViewGroup) findViewById(R.id.cord);
// With parentView = (ViewGroup) findViewById(R.id.<YOUR MAIN VIEW/PARENT CONTAINER>);
//R.id.cord is R.id.<YOUR MAIN VIEW/PARENT CONTAINER> for me because my Relative Layout
// container's name is cord.
for(int i=0; i < parentView.getChildCount(); i++) {
childView = parentView.getChildAt(i);
//The if may change there are other options try them too.
if(childView.getClass().getName().substring(35).equals("Button")){
buttons.add((Button)parentView.getChildAt(i));
}
/*
//Else part optional
//Remove comment to use
else
Log.e("Not","A Button");*/
}
for (int i =0;i<buttons.size();i++){
buttons.get(i).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//Do the work here
Log.d("Button Clicked",Integer.toString(view.getId()));
}
});
}
}
}
This is a way that you can solve your problem...
The best way: Just let your activity implement View.OnClickListener, and write your onClick method like this:
public void onClick(View v) {
final int id = v.getId();
switch (id) {
case R.id.button1:
// your code for button1 here
break;
case R.id.button2:
// your code for button2 here
break;
// even more buttons here
}
}
Then, in your XML layout file, you can set the click listeners directly using the attribute android:onClick:
<Button
android:id="#+id/button1"
android:onClick="onClick"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button 1" />
Yes, it can be achieved at the activity level programmatically. So no need to define the "onClick" attribute in XML.
You define a View.OnClickListener class. For e.g.
View.OnClickListener buttonListener = new View.OnClickListener() {
public void onClick(View v) {
// here you can define different code for different buttons
};
then you attach this listener to all your buttons on one place
final Button button = findViewById(R.id.button_id);
button.setOnClickListener(buttonListener);
Here's what I finally came to as solution it works only with touchables for instance TextView isn't a touchable:
In java:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final MainActivity activity = this;
/* Any kind of ViewGroup that is
parent of the common listener views. In the example it is the rootView */
View rootView = this.getWindow().getDecorView().getRootView();
// Buttons are touchables
ArrayList<View> touchables = rootView.getTouchables();
// Define the common on click listener for the buttons
View.OnClickListener listener = new View.OnClickListener() {
public final void onClick(View view) {
activity.onBtnClick( (Button) view );
}
};
// Iterate trough touchables and if the View is a button assign the listener
for (View v: touchables) {
// TODO: omit button if that common listener isn't meant for it
if(v instanceof Button) {
v.setOnClickListener(listener);
}
}
}
// The listener callback
protected final void onBtnClick(Button btn) {
String btnStringId = btn.getResources().getResourceEntryName(btn.getId());
}
In Kotlin:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
/* Any kind of ViewGroup that is
parent of the common listener views. In the example it is the rootView */
val rootView = window.decorView.rootView
val touchables = rootView.touchables
val listener = View.OnClickListener {
onBtnClick(it as Button)
}
touchables.forEach { if (it is Button) {
it.setOnClickListener(listener)
}}
}
protected fun onBtnClick(btn: Button) {
var btnStringId = btn.getResources().getResourceEntryName(btn.id)
}
Ok, I know there have been a lot of questions about SharedPreferences in Android asked before, and I did manage to get quite far, but since I'm kinda new to SharedPreferences I don't know the last few steps to get it to work.
In my MainActivity I have the following:
public class MainActivity extends ActionBarActivity
{
...
// Public static MainActivity so we can use findViewById from MyPrefsActivity
public static MainActivity mActivity;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
mActivity = this;
}
...
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
switch(id){
case R.id.action_settings:
startActivity(new Intent(this, MyPrefsActivity.class));
return true;
}
return false;
}
}
And this is MyPrefsActivity.java:
package com.example.checkboxoptionsv2;
import android.annotation.TargetApi;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.Preference.OnPreferenceChangeListener;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.ImageButton;
public class MyPrefsActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener
{
private static int prefs = R.xml.settings;
private ImageButton cbButton, spinnerButton, popupButton;
private final String LIST_PREFERENCE = "prefCheckboxOption";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try{
getClass().getMethod("getFragmentManager");
AddResourceApi11AndGreater();
}
catch(NoSuchMethodException e){ // Android API < 11
AddResourceApiLessThan11();
}
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
preferences.registerOnSharedPreferenceChangeListener(this);
* ListPreference listPreference = (ListPreference) findPreference(LIST_PREFERENCE);
if(listPreference.getValue() == null)
listPreference.setValue("0");
cbButton = (ImageButton) MainActivity.mActivity.findViewById(R.id.ibtnCheckbox);
spinnerButton = (ImageButton) MainActivity.mActivity.findViewById(R.id.ibtnSpinner);
popupButton = (ImageButton) MainActivity.mActivity.findViewById(R.id.ibtnPopup);
setChosenPreference(0);
}
private void setChosenPreference(int chosen_value){
// First put all Visibilities on GONE
cbButton.setVisibility(View.GONE);
spinnerButton.setVisibility(View.GONE);
popupButton.setVisibility(View.GONE);
// Then turn the chosen on VISIBLE again
switch(chosen_value){
case 0: // Multi-Click CheckBox
default:
cbButton.setVisibility(View.VISIBLE);
break;
case 1: // Dropdown CheckBox
spinnerButton.setVisibility(View.VISIBLE);
break;
case 2: // Pop-up CheckBox
popupButton.setVisibility(View.VISIBLE);
break;
}
}
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
if(key.equals(LIST_PREFERENCE)){
ListPreference listPreference = (ListPreference) findPreference(key); // LIST_PREFERENCE
listPreference.setOnPreferenceChangeListener(new OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
int chosen_option = Integer.valueOf((String) newValue);
setChosenPreference(chosen_option);
return false;
}
});
}
else{
// Other settings
}
}
#SuppressWarnings("deprecation")
protected void AddResourceApiLessThan11(){
addPreferencesFromResource(prefs);
}
#TargetApi(11)
protected void AddResourceApi11AndGreater(){
* MyPreferenceFragment pf = new MyPreferenceFragment();
getFragmentManager().beginTransaction().replace(android.R.id.content, pf).commit();
}
#TargetApi(11)
public static class MyPreferenceFragment extends PreferenceFragment{
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
* addPreferencesFromResource(MyPrefsActivity.prefs); // outer class
// private members seem to be visible for inner class, and
// making it static made things so much easier
}
}
}
And the settings.xml:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceCategory android:title="#string/checkbox_options_title" >
<ListPreference
android:key="prefCheckboxOption"
android:title="#string/pref_checkbox_option"
android:summary="#string/checkbox_options_summary"
android:entries="#array/checkbox_options"
android:entryValues="#array/checkbox_option_values" />
</PreferenceCategory>
</PreferenceScreen>
and arrays.xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="checkbox_options">
<item>CheckBox as Multi-Click</item>
<item>CheckBox as Dropdown</item>
<item>CheckBox as Pop-up</item>
</string-array>
<string-array name="checkbox_option_values">
<item>0</item>
<item>1</item>
<item>2</item>
</string-array>
</resources>
(Of course I've also included the MyPrefsActivity in the AndroidManifest.xml)
My goal is to make one of the three checkbox-option (found in the setChosenPreference method) VISIBLE, and the other two GONE, based on the preference selected in the ListPreference.
Right now the Listpreference in both the onCreate() method and onSharedPreferenceChanged() is null and giving a NullPointerException. So I set some breakpoints (see the three " * ") and the reason they are null is because the third " * " (in the static class PF) isn't called.
The addPreferencesFromResources should be called before using findPreference, otherwise it will return null. Does anyone know why during debugging I do get to the second " * " in the AddResourceApi11AndGreater() method, but I'm not getting to the third one in the MyPreferenceFragment-class onCreate method() ?.. the onCreate isn't called at all..
Also, does the rest of my code seems ok(-ish) or should I change something in order to make it work as I intended?
Thanks in advance for the responses.
TL;DR: MyPreferenceFragment instantion is created successfully, but it's #Override onCreate method is never called.
EDIT 1: Ok, I did found the problem: When I added addPreferencesFromResource(prefs) in the activity's onCreate method as a debug-test, I found out that the MyPreferenceFragment-class is indeed being initialized, then it finishes the activity's onCreate method (which would have failed at findPreference() if I didn't added the addPreferencesFromResource(prefs) test-line), and only after the activity's onCreate method is completely finished, it goes to the MyPreferenceFragment's onCreate method.
Is there a way to let the PreferenceFrament's onCreate method go first, while in the middle of the activity's onCreate method, so after AddResourceApi11AndGreater() but before findPreference(LIST_PREFERENCE)?
Move your logic to PF, don't do things in PreferenceActivity.
There are also changes in the way of listening to the preferences changes. Check the code.
public class MyPrefsActivity extends PreferenceActivity {
private static int prefs = R.xml.settings;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try{
getClass().getMethod("getFragmentManager");
AddResourceApi11AndGreater();
}
catch(NoSuchMethodException e){ // Android API < 11
AddResourceApiLessThan11();
}
}
#SuppressWarnings("deprecation")
protected void AddResourceApiLessThan11(){
addPreferencesFromResource(prefs);
}
#TargetApi(11)
protected void AddResourceApi11AndGreater(){
getFragmentManager().beginTransaction().replace(android.R.id.content,
new PF()).commit();
}
#TargetApi(11)
public static class PF extends PreferenceFragment implements SharedPreferences.OnSharedPreferenceChangeListener {
private ImageButton cbButton, spinnerButton, popupButton;
private final String LIST_PREFERENCE = "prefCheckboxOption";
#Override
public void onCreate(final Bundle savedInstanceState){
super.onCreate(savedInstanceState);
addPreferencesFromResource(MyPrefsActivity.prefs); // outer class
// private members seem to be visible for inner class, and
// making it static made things so much easier
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
preferences.registerOnSharedPreferenceChangeListener(this);
ListPreference listPreference = (ListPreference) findPreference(LIST_PREFERENCE);
if(listPreference.getValue() == null)
listPreference.setValue("0");
cbButton = (ImageButton) MainActivity.mActivity.findViewById(R.id.ibtnCheckbox);
spinnerButton = (ImageButton) MainActivity.mActivity.findViewById(R.id.ibtnSpinner);
popupButton = (ImageButton) MainActivity.mActivity.findViewById(R.id.ibtnPopup);
setChosenPreference(Integer.valueOf(preferences.getString(LIST_PREFERENCE, "0")));
}
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
int chosen_option = Integer.valueOf(sharedPreferences.getString(key, "0"));
setChosenPreference(chosen_option);
}
private void setChosenPreference(int chosen_value){
// First put all Visibilities on GONE
cbButton.setVisibility(View.GONE);
spinnerButton.setVisibility(View.GONE);
popupButton.setVisibility(View.GONE);
// Then turn the chosen on VISIBLE again
switch(chosen_value){
case 0: // Multi-Click CheckBox
default:
cbButton.setVisibility(View.VISIBLE);
break;
case 1: // Dropdown CheckBox
spinnerButton.setVisibility(View.VISIBLE);
break;
case 2: // Pop-up CheckBox
popupButton.setVisibility(View.VISIBLE);
break;
}
}
}
}
I implemented a bottom button bar(something like a tab bar controller in iPhone). For this I created a common layout (button_bar.xml, 5 image buttons) and included in other activity xml files. and for the managing the click action I created a BaseActivity.java extended from Activity and perform the click actions. and I extend other activity which need button bar from this BaseActivity, which works fine. Now I want to include a selected state to these buttons, but when I access the buttons in base activity it give a null pointer error. How can I solve this.
button_bar.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/bottomButtonBar"
style="#android:style/ButtonBar"
... >
<ImageButton
android:id="#+id/btnGuests"
android:onClick="showAllGuests"
android:src="#drawable/ic_guest_list" />
<ImageButton
android:id="#+id/btnAddGuest"
android:onClick="selectGuestType"
android:src="#drawable/ic_add_guest" />
<ImageButton
android:id="#+id/btnAddParty"
android:onClick="showAddParty"
android:src="#drawable/ic_add_party" />
....
</LinearLayout>
public class BaseActivity extends Activity {
// common to other activities.
public void showAddParty(View view) {
//showAddParty is one one of the buttons click method. 4 more buttons are there
Intent intent = new Intent(this, AddPartyActivity.class);
startActivity(intent);
// I can get "view.findViewById(R.id.btnAddParty)" here
// but I can't get "findViewById(R.id.btnAddGuest)" here. how this possible
}
}
public class AddPartyActivity extends BaseActivity{
....
}
Here i can get the corresponding view from parameter view, and change backgroundIbageSource. but when it goes to "AddPartyActivity" that inherited from Baseactivity, the new image is replaced by old one. How can I implement the selected feature in BaseActivity itself?
you can hold the state of the Button(clicked or not) using booloean in BaseActivity and check the value of these variables in AddPropertyActivity's onCreate() method.
public class BaseActivity extends Activity {
protected static boolean isButton1Clicked = false;
protected static boolean isButton2Clicked = false;
protected static boolean isButton3Clicked = false;
protected static boolean isButton4Clicked = false;
.....
public void showAddParty(View view) {
isButton1Clicked = true;
//showAddParty is one one of the buttons click method. 4 more buttons are there
Intent intent = new Intent(this, AddPartyActivity.class);
startActivity(intent);
}
}
public class AddPartyActivity extends BaseActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_layout);
Button button1 = (Button)findViewById(R.id.button1);
if(isButton1Clicked) {
button1.setBackground(R.drawable.clicked);
} else {
button1.setBackground(R.drawable.not_clicked);
}
......
......
}
}
and remember that all boolean variables must be static variables. (every object will have it's own copy of instance variables but all objects will share a single copy of static members).
public class BaseActivity extends Activity {
protected static boolean isButton1Clicked = false;
protected static boolean isButton2Clicked = false;
protected static boolean isButton3Clicked = false;
protected static boolean isButton4Clicked = false;
protected Button button1;
protected Button button2;
protected Button button3;
protected Button button4;
protected void checkButtonsState() {
if (isButton1Clicked) {
button1.setBackgroundResource(R.drawable.image1);
} else {
button1.setBackgroundResource(R.drawable.image2);
}
..........
}
public void showAddParty(View view) {
isButton1Clicked = true;
// showAddParty is one one of the buttons click method. 4 more
// buttons are there
Intent intent = new Intent(this, AddPartyActivity.class);
startActivity(intent);
}
}
public class AddPartyActivity extends BaseActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button1 = (Button) findViewById(R.id.button);
button2 = (Button) findViewById(R.id.item1);
.....
checkButtonsState();
}
}
Your error come from because you are using view.findViewById(), but the view variable correspond of the object that catch the click event (look in your xml, the 'android:onClick="showAddParty"').
So, you have in parameter a view instance that point directly to the btnAddParty button.
Is why you can access with findViewById to btnAddParty id but not btnAddGuest id.
You can access to all the view hierarchy by using direct findViewById as method of the activity class:
View btAddParty = findViewById(R.id.btnAddParty)
View btAddGuest = view.findViewById(R.id.btnAddGuest)
Now, you can have a full solution, by implement a special method (setMyInternalContent in the sample below) in the BaseActivity and keep an instance of each button, after, you just have to update there state on click action:
public class BaseActivity extends Activity {
protected Button mBtAddParty;
protected Button mBtAddGuest;
// ...
protected void setMyContentView(int resId) {
setContentView(resId);
mBtAddParty = (Button)findViewById(R.id.btnAddParty);
mBtAddParty = (Button)findViewById(R.id.btnAddGuest);
// ...
}
public void showAddParty(View view) {
mBtAddParty.setClickable(true);
mBtAddGuest.setClickable(false);
// ...
//showAddParty is one one of the buttons click method. 4 more buttons are there
Intent intent = new Intent(this, AddPartyActivity.class);
startActivity(intent);
}
}
public class AddPartyActivity extends BaseActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setMyContentView(R.layout.activity_layout);
// Do not forget to set initial button state:
mBtAddParty.setClickable(true);
mBtAddGuest.setClickable(false);
// ...
}
}
I have created 2 classes and one Interface. One Interface that handles dialog clicks,a MainActivity class that hold a button and a textView. The MainActiviy class instantiates my second class(FireMissilesFragment) which contains an AlertDialog as a fragment. In the FireMisslesFragment I have dynamically created EditText. The problem with my app is that when I call (onsavenstancestate) in my mainActivity class in which FireMissilesFragment is instantiated in, i try to save my editText values so that when the popup closes and I restart it, the values of editText will maintain it's values once the popup opens again.
I have tried (onSaveInstanceState) method and the values hold;however, it is yet possible for me to recreate what was destroyed once the dialog is initiated again.Can Someone please shed some light on this matter.
Here is my code:
//===============================Interface=====================================//
public interface NoticeDialogListener {
public void onDialogPositiveClick(DialogFragment dialog,EditText[] editText);
public void onDialogNegativeClick(DialogFragment dialog);
}
//==========================MainActivity Class=============================//
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends FragmentActivity implements ` NoticeDialogListener{
private EditText[] _edText;
private TextView _tv;
private Multiplication multi;
private Double[] s;
private String s1;
public static final String _SCORE1 = "score1";
public static final String _SCORE2 = "score2";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
_tv = (TextView)findViewById(R.id.textView1);
Button dAction = (Button)findViewById(R.id.button1);
s = new Double[2];
dAction.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {//open();
confirmFireMissiles();
}
});//ssetOnclickLi...
///success thank god.
//===================================================//
}
public void confirmFireMissiles() {
DialogFragment newFragment = new FireMissilesDialogFragment();
newFragment.show(getSupportFragmentManager(),"ff");
}//confirmFireMisslesClosing brace
// The below is what happens when the Button "multiply" in
Dialog window pops up.
#Override
public void onDialogPositiveClick(DialogFragment dialog,EditText[]
editText) {
_edText = editText; // is this association
multi = new Multiplication();
try{
// gets the text and stores to string array.
s[0]=Double.parseDouble(_edText[0].getText().toString());
s[1]=Double.parseDouble(_edText[0].getText().toString());
Log.d("hello", String.valueOf(s[0]));
}catch(NumberFormatException e){
_tv.setText("please Insert an Number and calculate again"); //
Log.d("Error", "place in numbers please");
}
s1 = String.valueOf(multi.multiply(s[0],s[1]));
//set Textview to s1.
_tv.setText(s1);
}
#Override
public void onDialogNegativeClick(DialogFragment dialog) {}
}
//================================================================================//
public class FireMissilesDialogFragment extends DialogFragment {
private AlertDialog.Builder builder;
private EditText[] _edText; // enable when ready
private NoticeDialogListener _mListener;
public static final String _SCORE1 = "score1";
public static final String _SCORE2 = "score2";
private Double[] s;
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the Builder class for convenient dialog construction
builder = new AlertDialog.Builder(getActivity());
//shows added content to dialog.
// d = new String[2];
s = new Double[2];
if(savedInstanceState !=null){
s[0] = Double.parseDouble(savedInstanceState.getString(_SCORE1));
s[1] = Double.parseDouble(savedInstanceState.getString(_SCORE2));
Log.d("Hey",String.valueOf(s[0]));
_edText[0].setText(String.valueOf(s[0]));
showIt();
}else{
showIt();
}
//sets the characterisitcs of the dialogue.
builder.setTitle("We are all stars of the show.");
builder.setMessage( "we are strong")
.setPositiveButton("Multiply", new
DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int id) {
// enable when ready
_mListener.onDialogPositiveClick(FireMissilesDialogFragment.this,_edText);
}
});
// Create the AlertDialog object and return it
return builder.create();
}
public void showIt(){
// This piece of code creates a Linear layout that is suppose to show in a dialogue popup.
LayoutParams param = new
LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT, 1.0f);
LinearLayout layout= new LinearLayout(getActivity());
layout.setLayoutParams(param);
layout.setOrientation(LinearLayout.VERTICAL);
layout.setBackgroundColor(Color.BLACK);
// Dynamically place EditText efficiently Inside Linear Layout.
_edText = new EditText[4];
for (int i = 0;i< _edText.length;i++) {
_edText[i] = new EditText(getActivity());
_edText[i].setInputType(InputType.TYPE_CLASS_NUMBER |
InputType.TYPE_NUMBER_FLAG_DECIMAL);
_edText[i].setTextSize(20)
try{
s[i] =Double.parseDouble(
_edText[i].getText().toString());
}catch(NumberFormatException e){
// Log.d("hello", "wrong input");
}
layout.addView(_edText[i]);
}
builder.setView(layout);
}
//============================================== Look over this code======////////////
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
//Verify that the host activity implements the callback interface
try {
// Instantiate the NoticeDialogListener so we can send events to the host
_mListener = (NoticeDialogListener) activity;
} catch (ClassCastException e) {
// The activity doesn't implement the interface, throw exception
throw new ClassCastException(activity.toString()
+ " must implement NoticeDialogListener");
}
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
// Save the user's current game state
savedInstanceState.putDouble(_SCORE1,s[0]);
savedInstanceState.putDouble(_SCORE2,s[1]);
super.onSaveInstanceState(savedInstanceState);
}
}
You could probably use SharedPreferences and store the information there, and then set the text of the text edit to the result of the shared preferences? or did I get the whole idea wrong?
here is an example of a simple save function:
SharedPrefrences scores = getSharedPreferences("key_name_here", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = scores.edit();
editor.putInt("key1", key1Var);
editor.putInt("key2", key2Var);
editor.commit();
and to retrive:
Var = getPrefrences(Context.MODE_PRIVATE).getInt("key1",default value);
That should probably do the trick
I am trying to figure out the best practice of communication between a TabActivity and the child activity embedded in this TabActivity.
In my TabActivity, there is a button. When the button is clicked, I want the child activity embedded in this TabActivity to be updated. I wrote the code like below, and just wonder whether it is a good practice. Thanks.
MyTabActivity.java
public class MyTabActivity extends TabActivity implements OnClickListener {
private TabHost m_tabHost;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ff_tab_activity);
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
m_tabHost = getTabHost();
TabHost.TabSpec spec;
Intent intent;
intent = new Intent().setClass(this, ChildActivity.class);
spec = m_tabHost.newTabSpec("Tab 1");
spec.setContent(intent);
tabView = (TextView) inflater.inflate(R.layout.tab_indicator, null);
spec.setIndicator(tabView);
m_tabHost.addTab(spec);
m_tabHost.setCurrentTab(0);
ImageView nextButtonIv = (ImageView) findViewById(R.id.next_button);
nextButtonIv.setOnClickListener(this);
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.next_button:
synchronized (ChildActivity.class) {
if (null != ChildActivity.s_childActivity) {
ChildActivity.s_childActivity.changeUI();
}
}
break;
}
}
ChildActivity.java
public class ChildActivity extends Activity {
public static ChildActivity s_childActivity;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
synchronized (MatchupsActivity.class) {
s_childActivity = this;
}
setContentView(R.layout.child_activity);
}
public void changeUi() {
code that changes UI
}
protected void onDestroy() {
super.onDestroy();
synchronized (MatchupsActivity.class) {
s_childActivity = null;
}
}
Since TabActivity is an ActivityGroup, I would use one of the following:
getCurrentActivity()
Returns the child tab activity being displayed. In your case, this method will return the instance of ChildActivity being used.
ChildActivity childActivity = (ChildActivity) getCurrentActivity();
getLocalActivityManager().getActivity(String)
Returns the child tab activity given its ID/tab spec name, whatever activity being displayed.
ChildActivity childActivity = (ChildActivity) getLocalActivityManager().getActivity("Tab 1");
I suggest overriding onNewIntent(Intent) in your ChildActivity:
Intent intent = new Intent();
intent.putExtra("xyz", "whatever"); // or a serializable
ChildActivity childActivity = (ChildActivity) getLocalActivityManager().getActivity("Tab 1");
childActivity.onNewIntent(intent);
Let me know if it works!
Seems fine. A couple of notes:
- I see no reason for synchronization.
- I'd replace
ChildActivity.s_childActivity.changeUI();
with
if(ChildActivity.s_childActivity != null){
ChildActivity.s_childActivity.changeUI();
}
or even
try{
ChildActivity.s_childActivity.changeUI();
} catch(Exception e){
//log
}
for added paranoid safety. :)
The way above with
ChildActivity childActivity = (ChildActivity) getLocalActivityManager().getActivity("Tab 1");
childActivity.onNewIntent(intent);
is not very nice. Instead of invoking your activity method directly (it can be null!!!) better do it this way:
Intent intent = new Intent(this, ChildActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
intent.putExtra(AlbumBrowser.INTENT_EXTRA_FILTER, mediaTitle);
getLocalActivityManager().startActivity("activityIdHere", intent);
Couple of design issues with this, but overall it seems reasonable.
I would forgo the static instance in the ChildActivity class. Why? Well, think about the relationship you're modeling. A TabActivity has a ChildActivity. This is textbook composition, and would be accomplished by adding a ChildActivity field to the TabActivity class, like so:
public class TabActivity {
private ChildActivity child;
//remember to initialize child in onCreate
//then, call methods using child.changeUI();, for example
}
This is better, because A) now I can have multiple instances of TabActivity and ChildActivity that won't interfere with each other (before, it was just a static variable, so only one ChildActivity could be used), and B) the ChildActivity is encapsulated inside the TabActivity class... before, it was a public field, meaning anything can use and modify it (might not be desirable; can often lead to some strange runtime bugs as well as messy, tied-together code) - we changed it to a private field, because we don't really want other classes accessing it in unexpected ways.
The only thing you may need access to from the ChildActivity is the parent (TabActivity). To do this, add the following methods and field to the ChildActivity class, and call the registerParent() method after constructing the ChildActivity:
public class ChildActivity ...{
private TabActivity parent;
public void registerParent(TabActivity newParent){
if (newParent != null){
parent = newParent;
}
}
}
So, if you need access to the parent TabActivity from the child, just call parent.someMethod();
It would also be wise to access fields like parent and child through getters and setters; it might save you some time in the long run.
You can use getParent() to obviate the need to do any of this.
Here's my launcher child class with buttons that switch between activities handled by the tabHost:
public class LaunchPadActivity extends Activity implements OnClickListener {
private static final int ICON_PROFILE = 0;
private static final int ICON_SEARCH = 1;
private static final int ICON_MAP = 2;
private static final int FAVOURITES = 3;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.launchpad);
GridView launchPad = (GridView) findViewById(R.id.launchpad);
launchPad.setAdapter(new LaunchIconAdapter(this));
}
public class LaunchIconAdapter extends BaseAdapter {
private Context mContext;
// references to our images
private Integer[] mThumbIds = { R.drawable.user, R.drawable.find,
R.drawable.map, R.drawable.favourites, R.drawable.reviews,
R.drawable.news, R.drawable.tutorial, R.drawable.info,
R.drawable.options, };
public String[] texts = { "Profile", "Search", "Map", "Favourites",
"Reviews", "News", "Tutorial", "Info", "Options" };
public LaunchIconAdapter(Context c) {
mContext = c;
}
// Number of thumbs determines number of GridView items
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
// Icon elements
LinearLayout launchIcon;
ImageView launchImage;
TextView launchText;
if (convertView == null) {
launchIcon = (LinearLayout) ((LayoutInflater) mContext
.getSystemService(LAYOUT_INFLATER_SERVICE)).inflate(
R.layout.launchicon, null);
} else {
launchIcon = (LinearLayout) convertView;
}
// Add ClickListener with metadata
launchIcon.setTag(new Integer(position));
launchIcon.setOnClickListener(LaunchPadActivity.this);
// Get subviews
launchImage = (ImageView) launchIcon
.findViewById(R.id.launch_image);
launchText = (TextView) launchIcon.findViewById(R.id.launch_text);
// Configure subviews
launchImage.setImageResource(mThumbIds[position]);
launchText.setText(texts[position]);
return launchIcon;
}
}
#Override
public void onClick(View v) {
int position = ((Integer) v.getTag()).intValue();
switch (position) {
case ICON_PROFILE:
Toast.makeText(this, "Profile", Toast.LENGTH_LONG).show();
break;
case ICON_SEARCH:
Toast.makeText(this, "Search", Toast.LENGTH_LONG).show();
((TabActivity) getParent()).getTabHost().setCurrentTab(1);
break;
case ICON_MAP:
Toast.makeText(this, "Map", Toast.LENGTH_LONG).show();
((TabActivity) getParent()).getTabHost().setCurrentTab(2);
break;
case FAVOURITES:
Toast.makeText(this, "Map", Toast.LENGTH_LONG).show();
((TabActivity) getParent()).getTabHost().setCurrentTab(3);
break;
}
}
}
Works like a charm.