Develop Reference

ANDROID: Delete textviews which are created dynamically

I have added multiple TextViews dynamically in a layout,
for(int x=4;x<result.length();x++)
{
JSONObject collegeData = result.getJSONObject(x);
Log.i("Classlist",""+x);
TextView tv = new TextView(this);
Animation animation = AnimationUtils.loadAnimation(student_profile.this, android.R.anim.slide_in_left);
tv.startAnimation(animation);
tv.setTag(tag);
tv.setLayoutParams(lparams);
tv.setText(collegeData.getString("date") + " " + collegeData.getString("day_name"));
tv.setTextSize(17);
this.linearLayout_top5classes.addView(tv);
}
This loop adds textViews according to the data received by the url,Now i want to remove the textviews which were created in this loop and i cant find a proper method to do so....I only want to remove these textviews and not all the textviews
UPDATE
First i used
int prv=0;
then
String tag ="textView_"+x;
prv++;
in the first loop to generate multiple tags
then i removed them with
for(int x=4;x<prv;x++)
{
View view = this.linearLayout_top5classes.findViewWithTag("textView_"+x);
this.linearLayout_top5classes.removeView(view);
Log.i("prv value",prv+"");
}

Of course there is a way. Just look for child views with tag:
View view = this.linearLayout_top5classes.findViewWithTag(tag);
this.linearLayout_top5classes.removeView(view);
If you add ID's to child views, then:
View view = this.linearLayout_top5classes.findViewById(id);
this.linearLayout_top5classes.removeView(view);

If possible try using different layout for the dynamically added textviews. and then remove views from second layout only. By using,:
linearLayout_top5classes.removeAllViews();

To remove particular view with tag
View view = this.linearLayout_top5classes.findViewWithTag(tag);
this.linearLayout_top5classes.removeView(view)
To remove view from particular position
this.linearLayout_top5classes.removeViewAt(position);
Use following logic to remove any view from layout.
this.linearLayout_top5classes..post(new Runnable() {
public void run() {
this.linearLayout_top5classes..removeView(view);
}
});

disable all elements in a layout - Android

In my Android app there is a requirement that a number of UI elements should be disabled until a button click carryout. Can I disable all the UI elements in a layout by referring the layout without disable them one by one. Is it possible.Can some one help me.

You could disable all views recursively like this.
Just pass the layout as view to the method:
private void enableViews(View v, boolean enabled) {
if (v instanceof ViewGroup) {
ViewGroup vg = (ViewGroup) v;
for (int i = 0;i<vg.getChildCount();i++) {
enableViews(vg.getChildAt(i), enabled);
}
}
v.setEnabled(enabled);
}
Just run enableViews(view, false) to disable, or enableViews(view, true) to enable again.

use following attribute in your xml layout( as a example textView)
android:visibility="gone"
in button click event
myText.setVisible(myText.VISIBLE)
you can either use them one by one or you can put all invisible content in a single layout and hide the layout. then once you want to show them, just VISIBLE the layout. then all will display
need any more comment.. just comment.

Clear previous View and show new View on button click in the same Activity

I have created an activity with two buttons at the top. One button to show "SMS Logs" and second to show "Call Logs".
On clicking "SMS Logs" button, i am dynamically creating textviews and linear layout to show sms logs.
On Clicking "Call Logs", i am dynamically creating another textviews and linear layout to show call logs.
But the problem is that, once if we click "sms log" button and then we click "call log" button, the previously created linear layouts are not removed and the both(previous layouts and the current layouts) are shown simultaneously.
But i want that the previous layouts should be removed on clicking the second button.
Which function, should i use to remove the previous viewgroups or the layouts. Tell me if you need to read my class file.
Edit:
This is my Activity's code,
public class General extends Activity
{
String phone, message;
TextView Logs;
View layout, callLayout;
TextView data, callData, line, callLine;
Button smsLog, callLog;
LinearLayout ll, callll;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.general_main);
Logs = (TextView)findViewById(R.id.Logs);
layout = findViewById(R.id.layout);
callLayout = findViewById(R.id.layout);
smsLog = (Button)findViewById(R.id.smsLogs);
callLog = (Button)findViewById(R.id.callLogs);
smsLog.setOnClickListener(new View.OnClickListener() {
public void onClick(View v)
{
callLayout.setVisibility(View.GONE);
ll = new LinearLayout(getApplicationContext());
ll.setOrientation(LinearLayout.VERTICAL);
data = new TextView(getApplicationContext());
data.setText("First Line");
data.setTextColor(Color.YELLOW);
line = new TextView(getApplicationContext());
line.setText("Second Line");
((ViewGroup) ll).addView(data);
((ViewGroup) layout).addView(line);
((ViewGroup) layout).addView(ll);
}
});
callLog.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
layout.setVisibility(View.GONE);
callll = new LinearLayout(getApplicationContext());
callll.setOrientation(LinearLayout.VERTICAL);
callData = new TextView(getApplicationContext());
callLine = new TextView(getApplicationContext());
callData.setText("Third Line");
callLine.setText("Fourth Line");
((ViewGroup) callll).addView(callData);
((ViewGroup) callLayout).addView(callLine);
((ViewGroup) callLayout).addView(callll);
}
});
}
}
I have removed the extra code and made it simple to understand.

You can use FrameLayout to solve your problem. But I recommend you to use tabview.Here is the link that demonstrates how to develop tabbed applications.Good Luck

You could implement a TabView.
But having your current setup just change the visibility of one view group to GONE and the other to VISIBLE.
GONE will make the view invisible and it won't take up any space anymore.
EDIT based on the code added to the question
Both your layout and callLayout are using the same XML view. Implement 2 identical views in your xml and keep one visible and one gone. This way when you set layout or callLayout visibility to GONE they are 2 different ones not the same. So your onClick() will have something like this:
for smsLog:
layout.setVisibility(View.GONE);
callLayout.setVisibility(View.VISIBLE);
for callLog:
callLayout.setVisibility(View.GONE);
callLayout.setVisibility(View.VISIBLE);

Dynamically loading the layout

In my app, i am loading a layout dynamically with text views ,on a button's onclick event. when i click the button for the first time , i got my layout with text views. when i click it again ,it should display the layout again. but its showing error. my code is
private OnClickListener some_name = new OnClickListener(){
public void onClick(View v) {
LinearLayout my_list_layout = (LinearLayout)findViewById(R.id.my_list_layout);
my_list_layout.setOrientation(1);
my_list_layout.setId(50);
my_textview = new TextView[length];
for(int i=0; i<length ; i++)
{
my_textview[i]= new TextView(getApplicationContext());
my_textview[i].setText("sample text");
my_textview[i].setId(i);
if(i==0)
{
RelativeLayout.LayoutParams my_textviewparams = new RelativeLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);
my_textviewparams.addRule(RelativeLayout.ALIGN_PARENT_TOP,my_list_layout.getId());
my_list_layout.addView(my_textview[i],my_textviewparams);
}
else
{
RelativeLayout.LayoutParams my_textviewparams = new RelativeLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,LinearLayout.LayoutParams.WRAP_CONTENT);
my_textviewparams.addRule(RelativeLayout.BELOW,my_textview[i-1].getId());
my_list_layout.addView(my_textview[i],my_textviewparams);
}
}
}
and my error log is
quick response is needed. anyone tell me, what is my wrong in coding, or what changes i have to do for my requirement?

You should remove this line:
my_list_layout.setId(50);
because once you set the id to 50, and again when you click the Button, the LinearLayout is null because you call findViewById(R.id. my_list_layout); its id has been changed to 50.
Cheers!

I got the answer.Here while i was doing first time the btn click, the child view will added to my parent view dynamically.
During the second click the i removed previously added child from my parent view and added the new child. So this will updates my content and displays clearly every time when I click the btn.
I got error in removing the views from my child, now I clear the error by assigning some variables for identifying btn click, whether user clicks it for first time or not. thank you all for your time here and for your answers.

Creating custom components using regular android components

basically I want to encapsulate a simple component from code that I already have.
Basically it's a LinearLayout with buttons inside. These buttons will make changes to a ListView, and there is also some other small stuff that it will do.
Currently I have a XML layout with those, and I programmatically setup everything else: the buttons, the interaction between the list and the other small stuff.
Obviously I thought to myself, let's encapsulate this.
I started out trying to extend the LinearLayout and adding the buttons.
Already I have no idea how to inflate the buttons to add to the view
What method do I override to create this buttons just before the view gets created without messing with the measures and inflations, etc.
I've looked around but the custom components I see are either completely new components or components that simply add small functionality to the custom ones.
Is there some guidelines for doing this?
Good tutorials/examples?
Any help is appreciated. Thanks !
EDIT:
Okay, here is a little more specific stuff.
Basically I want to create a View that holds filter buttons for a ListView. This will be used in different places with different filters, so I need flexibility for the buttons.
Basically I'd like to do something like this:
CustomView view = new CustomView(activity);
view.addButton("Lala", new OnFilterClickListener {
onClick(ListView list, View v) {
// Do the filtering
}
});
mListView.addHeaderView(view);
I want the view to adapt it's weights for showing the buttons, show the user which filter is active, stuff like that.
But I still don't really know how to make those dynamically added buttons appear, where do I generate them, how to inflate them and stuff like that.

public class myLayout extends LinearLayout {
//...
public void addButton(String text, OnClickListener listener) {
Button newButton = new Button(mContext);
newButton.setText(text);
newButton.setOnClickListener(listener);
//Say we want the weights to be equal
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0,LinearLayout.LayoutParams.Fill_PARENT, 1);
addView(newButton, params);
}
//...
}
You can even do something to the view before dispatching the click like this:
public class myLayout extends LinearLayout {
//...
public void addButton(String text, final OnClickListener listener) {
Button newButton = new Button(mContext);
newButton.setText(text);
newButton.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
//do whatever you want
//like change background of button or something
//finally
listener.onClick(v);
}
});
//Say we want the weights to be equal
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(0,LinearLayout.LayoutParams.Fill_PARENT, 1);
addView(newButton, params);
}
//...
}