I am starting to learn android and i have a few questions.
I have my main program as:
public class Radiation_overflowActivity extends Activity implements OnClickListener {
EditText init_cores;
View final_cores;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//Set up click listeners
init_cores=(EditText) findViewById(R.id.init_cores);
//init_cores.setOnClickListener(this);
final_cores=(View) findViewById(R.id.final_cores);
final_cores.setOnClickListener(this);
}
//called when a button is clicked
public void onClick(View v) {
switch (v.getId()){
case R.id.final_cores:
//int r = Integer.parseInt(init_cores.getText().toString().trim());
double initcores=Double.parseDouble(init_cores.getText().toString().trim());
double l=2,t=2;
double fcores=initcores*Math.exp(-l*t);
Intent i=new Intent(this,calcs.class);
i.putExtra("value",fcores);
startActivity(i);
break;
}
}
}
Also, my main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/initial_cores" />
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/init_cores"
android:inputType="numberDecimal" />
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/final_cores"
android:text="#string/calculate" />
</LinearLayout>
My calcs.java:
public class calcs extends Activity{
TextView calcs_final;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calcs);
calcs_final=(TextView) findViewById(R.id.calcs_final);
double f=getIntent().getExtras().getDouble("value");
calcs_final.setText(Double.toString(f));
}
}
My calcs.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/calcs_final"
android:text="#string/result" />
</LinearLayout>
I want to do this:
The user enters data into the edittext (init_cores) and then i want to make some calculations to compute the final_cores and show it to the user.
I have trouble for showing the results.I am starting another activity (calcs.class and calcs.xml).
Where i must do the calculations?To the calcs.class?
Right now,the user enters a number ,presses the "Calculate" button and then it shows the text (from the strings.xml) "Number of cores"" ,but not the result.
Also, can i use the input from the data and from my calculations and make a plot?If you could give me some directions to this.
Finally,is my approach right?
Thank you!
For plotting your data, you can use the AChartEngine library, which is quite extensive and easy to use.
As per I think your final_cores is a view on which, you want to get your edittext's value for calculation(Hope I am not wrong)
So, just do Something like,
public void OnClick(View v) {
switch (v.getId()){
case R.id.final_cores:
int r = Integer.parseInt(init_cores.getText().toString().trim());
Intent i=new Intent(this,calcs.class);
i.putExtra("value",r);
startActivity(i);
break;
}
}
Remove onClickListener from your init_cores edittext. And get values of r in your Calcs.class using
int r = getIntent().getExtras().getInt("value");
Also be sure in your edit text always you are entering numeric values so it can be parsable into Integer..
Try this and let me know what happen..
Thanks,
Related
I have a list of buttons in my activity_main, Once i clicked on Button_A it is taking me to the next list of buttons layout for eg. Button_A1.
And once i clicked Button_A1 it should show me the text which i have written in text_view. But here its getting failed. Once i Clicked in Button_A1, it showing like "your app is stopped". Can you guys help me on this, as i am new on this platform.
**Button_A1.xml:**
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="Small Text"
android:id="#+id/textView2"
android:layout_gravity="center_vertical"
android:onClick="Button_A1" />
</LinearLayout>
**button_A1.java:**
public class Ov1 extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ov1);
}
}
Do i have to give activity entry in manifest.xml. Please help me on this..
Button_A ----> Button_A1 ----> Textview
Clicked in Button_A1, it showing like "your app is stopped"
Because Button_A1 method is not available in Ov1 class. add method as:
public void Button_A1(View view) {
////
}
NOTE: To make TextView click-able need to add android:clickable="true" attribute in TextView xml
Here is my problem.
I've got a simple activity which set a layout, and add rows in a table-layout(itself in a scroll view).
Those table-rows have a custom layout with a text-field and a toggle button.
Each toggle button has a value taken from a database, and when I first create the activity, the values are OK. But when I turn the device and then change the orientation, all the toggles-button take "false" value. I printed the values that I set in the Logcat, and the values are the good ones (those in the database).
I thought something like the layout I want is hidden behind another layout, but I made some tests and the text-fields change with new values, so I really don't understand why the toggle buttons don't work.
Here is the code :
TableRow layout :
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<RelativeLayout
android:id="#+id/relativelayout_row_parametres"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:layout_weight="1.0">
<TextView
android:id="#+id/textview_row_parametres"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#android:color/black"
android:textStyle="bold"
android:textSize="20sp"
android:layout_marginLeft="2dp"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
/>
<ToggleButton
android:id="#+id/togglebutton_row_parametres"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="2dp"
android:textOn="#string/togglebutton_on"
android:textOff="#string/togglebutton_off" />
</RelativeLayout>
</TableRow>
Activity Layout :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<ImageView style="#style/header" />
<LinearLayout
android:layout_width="fill_parent" android:layout_height="0dp"
android:layout_weight="0.8"
android:background="#drawable/gradient_bg"
android:padding="10dip"
android:orientation="vertical">
<ScrollView
android:layout_width="fill_parent" android:layout_height="0dp"
android:layout_weight="0.85"
android:fillViewport="true"
android:padding="10dip"
android:layout_gravity="center">
<TableLayout
android:id="#+id/tablelayout_parametres"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#drawable/cornered_bg"
android:paddingTop="5dip"
android:paddingBottom="5dip">
</TableLayout>
</ScrollView>
<Button
android:id="#+id/button_parametres_accept"
android:gravity="center"
android:text="#string/accept_changes"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_weight="0.15"
android:layout_gravity="center_horizontal" />
</LinearLayout>
</LinearLayout>
And the activity code:
public class Parameters extends Activity {
#Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
}
#Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final Map<String, Boolean> changes = new HashMap<String, Boolean>();
final Context ctx = getApplicationContext();
LanguageManager.updateConfig(this);
setContentView(R.layout.parametres);
CountryDB[] countries = Database.instance(getApplicationContext()).getCountries();
TableLayout tabLayout = (TableLayout) findViewById(R.id.tablelayout_parametres);
for(int i =0; i<countries.length; i++){
TableRow newRow = (TableRow) getLayoutInflater().inflate(R.layout.row_parametres, null);
TextView textView = (TextView) newRow.findViewById(R.id.textview_row_parametres);
ToggleButton toggleButton = (ToggleButton) newRow.findViewById(R.id.togglebutton_row_parametres);
toggleButton.setChecked(countries[i].isToSynchronize());
toggleButton.setTag(countries[i]);
Log.e("setChecked",""+toggleButton.getId()+"/"+countries[i].isToSynchronize());
textView.setText(countries[i].getLabel());
toggleButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
CountryDB countryTemp = (CountryDB) v.getTag();
changes.put(countryTemp.getLabel(), ((ToggleButton)v).isChecked());
}
});
tabLayout.addView(newRow);
TableRow rowDivider = (TableRow) getLayoutInflater().inflate(R.layout.row_divider, null);
tabLayout.addView(rowDivider);
}
Button buttonValidation = (Button) findViewById(R.id.button_parameters_accept);
buttonValidation.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Iterator<String> iterator = changes.keySet().iterator();
while(iterator.hasNext()){
String stringTemp = iterator.next();
Database.instance(ctx).updateCountry(stringTemp, changes.get(stringTemp));
}
Intent intent = new Intent(ctx, Splash.class);
String result = "restart";
String from = "parameters";
Intent returnIntent = new Intent();
returnIntent.putExtra("result", result);
returnIntent.putExtra("from", from);
setResult(RESULT_OK, returnIntent);
startActivity(intent);
}
});
}
}
In the Log.e, I print the values, and they are good, the display on togglebuttons is wrong, they are just all "false".
Thanks for your help.
Between onCreate() and onResume() , Android tries to restore the old state of the toggle Buttons. Since they don't have unique ID's , Android wont succeed and everything is false again. Try to move your setChecked() calls into onResume() ( maybe onStart() works too).
Here is a pretty good answer to the same Question:
ToggleButton change state on orientation changed
you have to save data before Orientation.
Android have method onSaveImstamceState(Bundle outState) and onRestoreInstanceState(BundleInstaceState)
override these method in Activity.
There's a simpler solution: you only need to add configChanges property to your activity declaration, like stated here. This way you can prevent Activity restart when orientation changes. So in your manifest you should have something like
<activity android:name=".Parameters"
android:configChanges="orientation|keyboardHidden">
or if your buildTarget>=13
<activity android:name=".Parameters"
android:configChanges="orientation|keyboardHidden|screenSize">
Edit: Like reported on comments below, this is not an optimal solution. The main drawback is reported in a note of the document linked above:
Note: Handling the configuration change yourself can make it much more difficult to use alternative resources, because the system does not automatically apply them for you. This technique should be considered a last resort when you must avoid restarts due to a configuration change and is not recommended for most applications.
I have two layouts xml and can't get the second layout to work correctly.
A EditText placed on the second layout doesn't work as expected. It doesn't accept characters.
What am i missing here?
Should i use startActivity() instead?
Main.java
public class Main extends Activity implements View.OnClickListener {
EditText box1, box2;
#Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
showXml1();
}
public void onClick(View v) {
switch (v.getId()) {
case R.id.button1:
String box11 = box1.getText().toString();
Toast.makeText(this, box11,Toast.LENGTH_SHORT).show();
showXml2();
break;
case R.id.button2:
String box22 = box2.getText().toString();
Toast.makeText(this, box22,Toast.LENGTH_SHORT).show();
showXml1();
break;
}
}
public void showXml2() {
setContentView(R.layout.main2);
box2 = (EditText) findViewById(R.id.editText2);
}
public void showXml1() {
setContentView(R.layout.main);
box1 = (EditText) findViewById(R.id.editText1);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Main1" />
<EditText
android:id="#+id/editText1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<requestFocus />
</EditText>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button1"
android:onClick="onClick"
/>
</LinearLayout>
mail2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Main2" />
<EditText
android:id="#+id/editText2"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<requestFocus />
</EditText>
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button2"
android:onClick="onClick"
/>
</LinearLayout>
Use a meta layout xml file with a structure similar to this one:
meta_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<ViewFlipper
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/root">
<include
layout="#layout/main" />
<include
layout="#layout/main2" />
</ViewFlipper>
And then main.java:
public class Main extends Activity implements View.OnClickListener {
EditText box1, box2;
ViewFlipper root;
#Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.meta_main);
box1 = (EditText) findViewById(R.id.editText1);
box2 = (EditText) findViewById(R.id.editText2);
root = (ViewFlipper) findViewById(R.id.root);
}
public void onClick(View v) {
EditText editText = null;
switch (v.getId()) {
case R.id.button1:
editText = box1;
root.showNext();
break;
case R.id.button2:
editText = box2;
root.showPrevious();
break;
}
if(editText != null) {
Toast.makeText(this, editText.getText(), Toast.LENGTH_SHORT).show();
}
}
}
Hope it helps ;)
I don't think you can load a new layout that way.
Just put the two EditTexts in one XML and put one visible and the other invisble and with a button click vice versa.
As an alternative to different activities you might want to look at ViewFlipper http://developer.android.com/reference/android/widget/ViewFlipper.html
You are only allowed to call setContentView() once in your activity.
You can either
Create a "Main" layout that just contains a parent I.E. LinearLayout, or Relative layout
setContentView() on the parent. Then acquire a reference to it with findViewById() and call .addView() on your reference passing the inflated xml from one of these two files. .removeView() will allow you to switch to the other one when you like.
or
Include all of your views in one xml layout, but make half of them Visibility.GONE and when you want to switch just make the ones that were GONE be VISIBLE and vice versa
I think it should work, you have to reinitialize references for example every findViewById needs to be called again after calling setContentView(). You are exactly doing so first you are calling showXml1() & then you are clicking button1 which is executing Case1, you are getting the value of box1 & displaying it & then you are calling showXml2() & so on. I have tried your code & it works, i am wounding why its not working on your side?
Another thing is that it may not be a good idea if you have to call findViewbyId() a LOT OF TIMES, so you should avoid it i guess.
I try to get the effect click background color for linear layout. I've set clickable to linear layout. and from the code also I've put the click listener the setBackgroundResource.
Here it is the xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout
android:id="#+id/llinsertmem"
android:clickable="true"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="50px">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="PUSH it"
/>
</LinearLayout>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
/>
</LinearLayout>
and the java code:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
linearInsertMem.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
v.setBackgroundResource(android.R.drawable.list_selector_background);
Toast.makeText(testdoank.this, "succeded", Toast.LENGTH_SHORT)
.show();
}
});
}
When first time click the clickable linearlayout, the toast text is displayed but the background color click effect doesn't. The flash background click color is only work from the second click.
any idea what the problem is?
Is not necessary do anything in JAVA code.
You can only add this as attribute:
android:background="#android:drawable/list_selector_background"
And it works for me (on Android 2.2 device)
After try and error, somehow it's work.
just put the setBackgroundResource also on the onCreate.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
linearInsertMem.setBackgroundResource(android.R.drawable.list_selector_background);
linearInsertMem.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
v.setBackgroundResource(android.R.drawable.list_selector_background);
Toast.makeText(testdoank.this, "succeded", Toast.LENGTH_SHORT)
.show();
}
});
}
Don't know the logic explanation. if you have a thought, please.
In the onClick method you are using v as the View which is passed, but that view may not be the LinearLayout which you want to change the background.
Thus you need to create a class level variable or a final varibale and pass the handle for the LineraLayout to the onClick method.
Remove/cut from onCreate:
linearInsertMem.setBackgroundResource(android.R.drawable.list_selector_background);
and paste it into onClick or change v. into linearInsertMem.
I think that Exlipse will then demand that linearInsertMem must be final like:
final LinearLayout linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
Or you can define this object above onCreate like this:
LinearLayout linearInsertMem;
then in onCreate you state:
linearInsertMem = (LinearLayout)findViewById(R.id.llinsertmem);
then onClick method will know exactly which view you want to change if you use linearInsertMem.setBackgroundResource...
I know this is so easy (doh...) but I am looking for a way to run a method on tapping or clicking a TextView line of text in an Android App.
I keep thinking about button listeners and anonymous method listener calls, but it just does not seem to apply to TextView.
Can someone point me at some code snippet to show how clicking or tapping on a piece of text in a TextView runs a method?
You can set the click handler in xml with these attribute:
android:onClick="onClick"
android:clickable="true"
Don't forget the clickable attribute, without it, the click handler isn't called.
main.xml
...
<TextView
android:id="#+id/click"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click Me"
android:textSize="55sp"
android:onClick="onClick"
android:clickable="true"/>
...
MyActivity.java
public class MyActivity extends Activity {
public void onClick(View v) {
...
}
}
This may not be quite what you are looking for but this is what worked for what I'm doing. All of this is after my onCreate:
boilingpointK = (TextView) findViewById(R.id.boilingpointK);
boilingpointK.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if ("Boiling Point K".equals(boilingpointK.getText().toString()))
boilingpointK.setText("2792");
else if ("2792".equals(boilingpointK.getText().toString()))
boilingpointK.setText("Boiling Point K");
}
});
OK I have answered my own question (but is it the best way?)
This is how to run a method when you click or tap on some text in a TextView:
package com.textviewy;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;
public class TextyView extends Activity implements OnClickListener {
TextView t ;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
t = (TextView)findViewById(R.id.TextView01);
t.setOnClickListener(this);
}
public void onClick(View arg0) {
t.setText("My text on click");
}
}
and my main.xml is:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<LinearLayout android:id="#+id/LinearLayout01" android:layout_width="wrap_content" android:layout_height="wrap_content"></LinearLayout>
<ListView android:id="#+id/ListView01" android:layout_width="wrap_content" android:layout_height="wrap_content"></ListView>
<LinearLayout android:id="#+id/LinearLayout02" android:layout_width="wrap_content" android:layout_height="wrap_content"></LinearLayout>
<TextView android:text="This is my first text"
android:id="#+id/TextView01"
android:layout_width="wrap_content"
android:textStyle="bold"
android:textSize="28dip"
android:editable = "true"
android:clickable="true"
android:layout_height="wrap_content">
</TextView>
</LinearLayout>
from inside an activity that calls a layout and a textview, this click listener works:
setContentView(R.layout.your_layout);
TextView tvGmail = (TextView) findViewById(R.id.tvGmail);
String TAG = "yourLogCatTag";
tvGmail.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View viewIn) {
try {
Log.d(TAG,"GMAIL account selected");
} catch (Exception except) {
Log.e(TAG,"Ooops GMAIL account selection problem "+except.getMessage());
}
}
});
the text view is declared like this (default wizard):
<TextView
android:id="#+id/tvGmail"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/menu_id_google"
android:textSize="30sp" />
and in the strings.xml file
<string name="menu_id_google">Google ID (Gmail)</string>
Although you can resolve the problem by setting the listener to textview, it's recommended not to. You should use flat button as it is a subclass of Button and it provides many attributes which TextView doesn't.
To use flat button, add style="?android:attr/borderlessButtonStyle" attribute -
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="DONE"
style="?android:attr/borderlessButtonStyle"/>
in textView
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:onClick="onClick"
android:clickable="true"
You must also implement View.OnClickListener and in On Click method can use intent
Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
intent.setData(Uri.parse("https://youraddress.com"));
startActivity(intent);
I tested this solution works fine.
To click on a piece of the text (not the whole TextView), you can use Html or Linkify (both create links that open urls, though, not a callback in the app).
Linkify
Use a string resource like:
<string name="links">Here is a link: http://www.stackoverflow.com</string>
Then in a textview:
TextView textView = ...
textView.setText(R.string.links);
Linkify.addLinks(textView, Linkify.ALL);
Html
Using Html.fromHtml:
<string name="html">Here you can put html <a href="http://www.stackoverflow.com">Link!</></string>
Then in your textview:
textView.setText(Html.fromHtml(getString(R.string.html)));
You can use TextWatcher for TextView, is more flexible than ClickLinstener (not best or worse, only more one way).
holder.bt_foo_ex.addTextChangedListener(new TextWatcher() {
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// code during!
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// code before!
}
#Override
public void afterTextChanged(Editable s) {
// code after!
}
});