Develop Reference

android: one click listener on many imageviews in layout

I have the following scenario:
In a layout, I have imageviews aligned horizontally and vertically as shown in image.
First, which layout should be used for this purpose? RelativeLayout or FrameLayout? ListView inside the layout?
Also, instead of writing setOnClickListener for every imageview, how can I write just one click listener to get the clicked imageview?

A GridView is perfect for this. For more information on GridView, look here.
As for your onClickListener question: there is no easy way to do this, but what you can do is something like this:
Have an array containing every ImageView id like so:
public static final int[] IMAGE_VIEWS = {R.id.imageView1, R.id.imageView2, R.id.imageView3 /*etc*/}; //Make sure to list from the first imageview to the last image view in correct order
Define an onClickListener
private View.OnClickListener imageViewListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
for (int i = 0; i < IMAGE_VIEWS.length; i++) {
if (v.getId() == IMAGE_VIEWS[i]) {
doSomethingWithImageViewClick(i); //if ImageView 4 was clicked, variable 'i' will be 3 (because arrays start at index = 0).
}
}
}
}
Set the onClickListeners for all your imageViews:
final ImageView view1 = (ImageView) view.findViewById(R.id.imageView1);
view1.setOnClickListener(imageViewListener);
//etc

Use 'GridView' in the layout and use 'setOnItemClickListener' to handle click events,
You can find more details in below link
GridView.

GridView can achieve the effect. I think you can look at this Grid View.

OnTouchListener on invisible view

so all I want to do is to touch on a certain part of the screen where an invisible view is hidden.
After that touch the view should fade In.
The Problem: The Listener isn't triggered whe I touch the view.
Things I've tried: view.setImageAlpha(0), view.setAlpha(0), view.setVisibility(View.INVISIBLE)
When I set alpha=1 the listener works fine.
Thanks in advance.
Edit:
Thanks to #Viswanath L for the great solution which he mentioned in his post as second workaround.
I just wanted to give a little code example for that in case someone doesn't know how this works:
What I want: I want to touch the right corner of the screen and at this spot, a view(myView) should fade in.
fadeInListener = new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
System.out.println("TRIGGERED");
//The screen size here is 1080x1920(vertical)
if (event.getRawX() > 800 && event.getRawY() > 1640) {
final AlphaAnimation fadeIn = new AlphaAnimation(0, 1);
fadeIn.setDuration(500);
fadeIn.setFillAfter(true);
myView.startAnimation(fadeIn);
}
}
return false;
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
layout.setOnTouchListener(fadeInListener);
}
The layout is:
this.layout = (RelativeLayout) findViewById(R.id.layout);
And myView should be placed in the right corner and what's very important:
myView.setVisibility(View.Gone);
Hope this helps.

INVISBLE means you are trying to add a listener to a view which is not there. You can add the listener to a visible view only.
WORKAROUND
1) Try to make a dummy view which is visible but having the same color as background.
2) Try to set the listener for parent and check the position (whether the position does
belongs to INVISIBLE view).

onTouchListener does not trigger for an invisible View. You can make 2 exactly the same views one under another the one below having the map. It will be visible and so it can be touched but it will be obscured by the view above like they do here: http://blahti.wordpress.com/2012/06/26/images-with-clickable-areas/

Try this in your xml:
<View
android:id="#+id/my_inv_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/blue"
/>
<View
android:id="#+id/my_touch_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
And set up the click listener like this:
final View mTouchView = findViewById(R.id.my_touch_view);
final View mInvView = findViewById(R.id.my_inv_view);
mInvView.setVisibility(View.INVISIBLE);
mTouchView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mInvView.setVisibility(View.VISIBLE);
}
});

TextView Scrollable

I set my TextView to be scrollable:
textView.setMovementMethod(new ScrollingMovementMethod());
But, when I update my TextView's texts, the scrolling position keeps at the last text position, resulting in, sometimes, the text getting invisible and then, I need to move the scroll to see the new text (I update with: textView.setText(newText)).
I tried those codes, but no changes were noted:
textView.invalidate();
textView.requestLayout();
textView.scrollBy(0, 0)
textView.scrollTo(0, 0);
P.S.: the textView is a child of a RelativeLayout.

Why don't you just use a ScrollView in xml will be much easier open the ScrollView open a layout set it how you want it to be horizontal or vertical put your TextViews in and then close first the layout and then ScrollView and Voila done..

What I did to solve my problem:
textView.post(new Runnable() {
#Override
public void run() {
textHeight = textViews.getLineHeight() * textViews.getLineCount();
if (textHeight > relativeLayout.getHeight())
textView.setMovementMethod(new ScrollingMovementMethod());
else
textView.setMovementMethod(null);
}
});

How to add Buttons dynamically into ScrollView

I'm having a difficulty adding buttons dynamically to a ScrollView. The code below is adding the buttons BUT there is no scroller.
If I'm putting the buttons directly in the XML (not dynamically) it's working and I can scroll down/up.
My view:
<ScrollView android:id="#+id/ScrollView01"
android:layout_width="264dp"
android:layout_height="match_parent"
android:fillViewport="true"
>
<LinearLayout
android:id="#+id/buttons"
android:layout_width="264dp"
android:layout_height="wrap_content"
android:orientation="vertical"
android:scrollbars="vertical"
>
** HERE THE BUTTONS SHOULD BE ADDED DYNAMICALLY **
</LinearLayout>
</ScrollView>
The code which adding buttons:
// create new button
final Button newbutton = new Button(this);
// set background color
newbutton.setBackgroundColor(Color.GRAY);
// set width and height
newbutton.setWidth(50);
newbutton.setHeight(20);
// set position
newbutton.setY(((float)numOfButton*20)+20);
newbutton.setX(100);
// set text
newbutton.setText(Integer.toString(numOfButton));
// create patameter
final LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT
);
//set listener
android.view.View.OnClickListener buttonListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
// make all the DrawView invisible
for(View view : comments){
view.setVisibility(View.INVISIBLE);
}
// set the chosen comment visible
comments.get(numOfButton).setVisibility(View.VISIBLE);
boardsHandler.setCurrenBoard(numOfButton);
}};
newbutton.setOnClickListener(buttonListener);
// creating a thread to add button
buttons.post(new Runnable() {
#Override
public void run() {
buttons.addView(newbutton, p);
}
});
Is it something with the LinearLayout.LayoutParams p ?
Thanks!

Try following code
first do
LinearLayout myContainer = findViewById(R.id.layoutId);
When you set parameters for a view, they need to correspond to the parent view for your widget.
LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.FILL_PARENT);
finally add button as you are doing.
try and tell if it works

Setting X and Y position will not work. The LinearLayout layouts it's children vertically or horizontally, only taking their width/height into account.
Besides this -- have you tried calling buttons.invalidate() after buttons.addView(...). This should refresh the layout and should show your newbutton.

This is a rather old post but I found it quickly when doing research on that kind of problem. So I'll post am answer anyway, maybe it'll be of help to anyone..
I had a similar problem with a relative layout to which buttons were added dynamically. I found a workaround in defining the layout's size manually when adding the buttons. For your case, adding the line
buttons.getLayoutParams().height = numOfButton*20+40;
after
buttons.addView(newbutton, p);
might help, though it's probably not the best solution.
I thought my mistake was using the RelativeLayout at all, but since you appear to have the same problem...
Ever thought of using a table layout?

How I can increase the touch area for controls (ToggleButton)?

I have a ToggleButton. I want to have more place for click on this button. If I add layout_width, layout_height etc. the image looks bad. I also tried using android:padding but it did not help me.
It is needed for the convenience of users.

Easy solution : If you have image for the button, then create transparent area around it (i.e. for touch area).
The grey area can be transparent to increase the touch area.
Or use TouchDelegate

You can also increase touch area by setting touch delegates Android Developer Training Blog Post
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the parent view
View parentView = findViewById(R.id.parent_layout);
parentView.post(new Runnable() {
// Post in the parent's message queue to make sure the parent
// lays out its children before you call getHitRect()
#Override
public void run() {
// The bounds for the delegate view (an ImageButton
// in this example)
Rect delegateArea = new Rect();
ImageButton myButton = (ImageButton) findViewById(R.id.button);
myButton.setEnabled(true);
myButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Toast.makeText(MainActivity.this,
"Touch occurred within ImageButton touch region.",
Toast.LENGTH_SHORT).show();
}
});
// The hit rectangle for the ImageButton
myButton.getHitRect(delegateArea);
// Extend the touch area of the ImageButton beyond its bounds
// on the right and bottom.
delegateArea.right += 100;
delegateArea.bottom += 100;
// Instantiate a TouchDelegate.
// "delegateArea" is the bounds in local coordinates of
// the containing view to be mapped to the delegate view.
// "myButton" is the child view that should receive motion
// events.
TouchDelegate touchDelegate = new TouchDelegate(delegateArea,
myButton);
// Sets the TouchDelegate on the parent view, such that touches
// within the touch delegate bounds are routed to the child.
if (View.class.isInstance(myButton.getParent())) {
((View) myButton.getParent()).setTouchDelegate(touchDelegate);
}
}
});
}
}

Use TouchDelegate for your ToggleButton as ammar26 have commented you.
Or
Try this:
Make one parent layout like LinearLayout or RelativeLayout that cover the ToggleButton. And now put margin to that Parent layout.
Now, on click of that Parent layout do action for the toggle button.
Hope it will help you to increase touch area for your view.
Happy Coding.

Instead of putting the touch event in button put it in the layout containg the only the button..and fix the size of the layout as ur wish

increase the values of android:padding:
<SeekBar android:id="#+id/seek" android:layout_width="0dip"
android:layout_height="wrap_content" android:layout_weight="1"
android:paddingTop="5dp" android:paddingBottom="5dp"
android:progressDrawable="#drawable/green_scrubber_progress_horizontal_holo_ligh‌​t"
android:thumb="#drawable/thumb" />

Take the margin (place of padding) of your Button from its parent layout and then perform opration on your Layout
mLayout.setonTouchListener(View.onTouchListener{
// here your working code
});