Develop Reference

One activitiy with different backgrounds in android

I am trying to create an android app. I have two buttons next and back in my android app. I want when i click on next button its open same activity with different background. Next time i again click next new background image. And on press on back button its show previous image. And if no previous image its shows menu on press. Similarly if background with last image its hide next button. I have no idea how to do this.
I have tried this:
#Override
public void onCreate(Bundle savedInstanceState)
{
onCreate(savedInstanceState);
back = (Button) findViewById(R.id.back);
next = (Button) findViewById(R.id.next);
back.setOnClickListener(this);
next.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if(v.getId()==R.id.back)
{
startActivty(new Intent(this,));
}
else if(v.getId()==R.id.next)
{
startActivity(newIntent(this,));
}
}
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"
android:background="#drawable/back">
<Button
android:id="#+id/back"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_marginBottom="25dp"
android:background="#drawable/ques"
android:text="Back" />
<Button
android:id="#+id/next"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/back2"
android:layout_alignBottom="#+id/back2"
android:layout_alignParentRight="true"
android:background="#drawable/ques"
android:text="Next" />
</RelativeLayout>
In layout as you can see i am using image back for background. I want when i click next new background image then next and so on.
But i dont know how to start same activity with differene backgroud.

Don't start new Activity just change the background:
Keep an array of background resources in your activity like:
int[] backgroundResId;
and one int variable to store current background index:
int currentIndex=0;
now inside your onCreate initialize this array with resource id's of all the backgrounds drawables:
backgroundResId=new int[]{R.drawable.a,R.drawable.b,R.drawable.c};
changeBackground()
create function changeBackground in activity:
private void changeBackground(){
findViewById(R.id.root_layout).setBackgroundResource(backgroundResId[currentIndex]);
}
Now onClick of next button increase currentIndex:
currentIndex++;
if(current<=backgroundResId.length){
changeBackground();
}else{
// setVisibility of next button to invisible
}
onBackButton Click
currentIndex--;
if(current>=0){
changeBackground();
//// setVisibility of next button to visible
}else{
//show menu
}

Make an images array and post your data to the next activity:
Intent intent = getIntent();
intent.putExtra("background", imageIdInTheImageArray);
startActivity(intent);
//finish();
and in your onCreate function :
Bundle b = getIntent().getExtras();
if (b != null) {
int background = b.getInt("background");
//set your background
}

You can add an ImageView in your xml file.
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
you can change background using this
ImageView imageView = (ImageView) findViewById(R.id.imageView);
imageView.setBackgroundResource(resId);

Try this..
Global:
int[] backgrounds = new int[]{ images in drawable as int array };
int count = 0;
Button back,next;
RelativeLayout img_backn_lay;
JAVA:
setContentView(R.layout.activity_main);
back = (Button) findViewById(R.id.back);
next = (Button) findViewById(R.id.next);
back.setOnClickListener(this);
next.setOnClickListener(this);
img_backn_lay = (RelativeLayout) findViewById(R.id.main_lay);
img_backn_lay.setBackgroundResource(backgrounds[count]);
count += 1;
ClickListener:
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(v.getId()==R.id.next)
{
if(backgrounds.length != count){
img_backn_lay.setBackgroundResource(backgrounds[count]);
count += 1;
}else{
Toast.makeText(MainActivity.this, "No images", Toast.LENGTH_LONG).show();
}
}
else if(v.getId()==R.id.back)
{
if(count != 0){
img_backn_lay.setBackgroundResource(backgrounds[count]);
count -= 1;
}else{
Toast.makeText(MainActivity.this, "No images", Toast.LENGTH_LONG).show();
}
}
}
XML:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/main_lay"
android:layout_width="match_parent"
android:layout_height="match_parent" >

android handle both scroll and click events on a TextView

I have a problem with my android app. I'm using a simple Textview with a vertical scrollBar to display lyrics from a song. The problem is that in my activity I set a Onclick event on this same Textview. So when I scroll the lyrics in the textview, the activity registers a click event when I release my finger from the screen. I don't want the onClick event to happen after I scroll.
Here is what I have done so far but it does not work really well since im using a onLongClick event wich is not precise enough:
public class NowPlayingActivity extends Activity implements ckListener,OnLongClickListener
{
private TextView lyrics;
private static final String TAG_LYRICS = "LYRICS";
#Override
protected void onCreate(Bundle savedInstanceState)
{
this.lyrics = (TextView) this.findViewById(R.id.now_playing_Lyrics);
this.lyrics.setOnClickListener(this);
this.lyrics.setMovementMethod(new ScrollingMovementMethod());
this.lyrics.setOnLongClickListener(this);
}
public void onClick(View v)
{
String tag = (String) v.getTag();
if (tag.equals(NowPlayingActivity.TAG_LYRICS))
{
if (this.scrolled) //this way, the click action doesnt occur after a scroll
{
this.scrolled = false;
}
else
{
this.scrolled = false;
this.artwork.setVisibility(View.VISIBLE);
this.lyrics.setVisibility(View.GONE);
}
}
public boolean onLongClick(View arg0)
{
this.scrolled = true;
return this.scrolled;
}
what can I do to make it more "accurate" (so I dont have to make a longClick for it to work)
thanks!

Put your textview inside scrollview.
<ScrollView
android:id="#+id/content_scroll"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_margin="7dip"
android:scrollbars="none" >
<TextView
android:id="#+id/fileContent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dip" />
</ScrollView>
Then it should work properly. Hope it helps

Getting Array index on item click

I have created an Android RSS Reader App.I have a text marquee in my android app.Iam fetching RSS feed and store RSS title as an array.Iam setting this array as the marque text.Check the code,
String MarqueeStr="";
TextView flashnews;
for (int i = 0; i < nl.getLength(); i++) {
MarqueeStr = MarqueeStr +" | "+ Headlines.Title[i];
}
flashnews.setText(MarqueeStr);
Now I have to set an onclick listener for my marquee, so that user can view detailed description of title which they are clicked.I know how to set it.But my problem is, how can i get the array index of clicked string in the marquee text when a user click on the marquee?
here is my XML layout,
<TextView
android:id="#+id/flashs"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:lines="1"
android:ellipsize="marquee"
android:layout_marginLeft="70dp"
android:fadingEdge="horizontal"
android:marqueeRepeatLimit="marquee_forever"
android:scrollHorizontally="true"
android:singleLine="true"
android:textColor="#e7e7e7" />
screen shote here..
can you see that "Latest News"? its my marquee text

I think that will only be possible if you will create your textviews dynamically and set id for them. like if you are having 10 news link then use 10 textviews
TextView txt = null;
View.OnClickListener marquee_click = new View.OnClickListener() {
#Override
public void onClick(View v) {
int selected_item = v.getTag();
switch (selected_item) {
case 0:
break;
case 1:
break;
case 2:
break;
default:
break;
}
}
};
LinearLayout news_text_layout = new LinearLayout(getApplicationContext());
news_text_layout.setOrientation(LinearLayout.HORIZONTAL);
for (int i = 0; i < 10; i++) {
txt = new TextView(getApplicationContext());
txt.setTag(i); // OR txt.setId(i);
txt.setText("new " + i);
txt.setOnClickListener(marquee_click);
news_text_layout.addView(txt);
}
// ADD YOUR LINEAR LAYOUT ON WHICH YOU HAVE ADDED ALL TEXT VIEW IN YOUR LISTVIEW FOOTER.
// NOW PERFORM SAME ANIMATION OR TRICK ON LINEAR LAYOUT WHICH YOU WERE PERFORMING ON marquee text.
Hope it can help you...

You can add every FlashNews as a dynamically created TextView. And you can put all of these in
one HorizontalScrollView. And set their listeners seperatly.
For marquee function, you can programmatically scroll the horizontalView within your code.
I dont know if it's possible to make it with your idea. (Actually it can be done, but it will contain pain i guess)

for animation look at this i have just created.
Create new project then add class and xml file which i am giving.
public class Test_stflowActivity extends Activity {
LinearLayout ll = null;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final LinearLayout ll = (LinearLayout) findViewById(R.id.linearLayout1);
final TranslateAnimation ts = new TranslateAnimation(200, -100, 0, 0);
ll.setAnimation(ts);
ts.setDuration(5000);
TextView tv = new TextView(getApplicationContext());
tv.setText("*bharat sharma*");
tv.setTextSize(30);
ll.addView(tv);
ll.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
ll.startAnimation(ts);
}
});
}
}
this is xml file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/RelativeLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true" >
</LinearLayout>
</RelativeLayout>
it is working for me

if you use a ListView with an adapter, (which you should), you can use the getItem(int position) function to get the specific item.

Dynamic set image path

In my project, there are a number of images having back and forward images and all images having a common layout. On clicking back and next buttons new images should be displayed.
private int imageCounter = 0;
private ImageView imageView;
private int[] imageArray = {R.drawable.image_w_lbl_0, R.drawable.image_w_lbl_1,};
private int index_count = 0;
#Override
public void onCreate(Bundle savedInstanceState)
{
setContentView(R.layout.frame0);//this one is the common parent layout for all imageviews
super.onCreate(savedInstanceState);
imageView = new ImageView(this);
ImageButton next = (ImageButton) findViewById(R.id.next);
ImageButton back = (ImageButton) findViewById(R.id.back);
next.setOnClickListener(this);
back.setOnClickListener(this);
//show the default image
this.loadImage(imageArray[0]);
}
#Override
public void onClick(View v)
{
int imagePath = 0;
// TODO Auto-generated method stub
switch (v.getId())
{
case R.id.next:
if(imageCounter < 25)
{
imagePath = imageArray[index_count];
}
imageCounter++;
break;
case R.id.back:
if(imageCounter > 0)
{
//imagePath =
}
imageCounter--;
break;
}
this.loadImage(imagePath);
}
private void loadImage(int imagePath)
{
imageView.setImageResource(imagePath);
}
I am able to see my layout only in the output having back and forward buttons with the black background not an image from my drawable folder.
XML Layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center">
<ImageButton android:id="#+id/back" android:src="#drawable/btn_back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"/>
<ImageButton
android:id="#+id/next"
android:src="#drawable/btn_next"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right" />
</LinearLayout>

int array of images from resources (i.e. res/drawable-mdpi):
Integer[] imageArray = { "R.drawable.img1", "R.drawable.img2" }
...
imageView.setImageResource(imageArray[0]); // displays img1

Not very clear what you are asking, but do you want to do something like this:
imagePath=R.drawable.image_wo_lbl_0;
You can store image path in this way, if you actually want to do this.

imageView.setImageResource(R.drawable.img1)

Easiest way - Can be consider the below code
We can take advantage of Imageview setImageResource , refer below code for the same.
put image in the drawable like the below order
image_1.png, image_2.png, etc.
int imagePosition = 1;
int resId = getResources().getIdentifier("image_" + imagePosition, "drawable", getPackageName());
imageview.setImageResource(resId);

Use ContextCompat to get drawable(Image in your case). This is one of the new ways to set image to your image view.
imageView.setImageDrawable(ContextCompat.getDrawable(getApplicationContext(),
R.drawable.your_image));
You can use ContextCompat to get colors as well.
I use it in my apps and it works properly.

Android: swapping two overlapping views

Can anyone tell me what's wrong with this implementation? All I want to do here is have two overlapping views that swap places when you tap the screen. Unless I'm just using it wrong, View.bringToFront() does nothing?
Below is all the code in my app. Note that I added padding to the 'backView' just to make sure the two were actually overlapping. Indeed I could see both on the screen. While tapping the top view does indeed trigger the onClick method, nothing visibly changes in response to the calls to bringToFront.
public class MainActivity extends Activity implements OnClickListener {
private ImageView frontView;
private ImageView backView;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
frontView = (ImageView) findViewById(com.example.R.id.FrontView);
backView = (ImageView) findViewById(com.example.R.id.BackView);
frontView.setOnClickListener(this);
backView.setOnClickListener(this);
backView.setPadding(10,0,0,0);
}
private boolean flag;
public void onClick(View v) {
if (!flag) {
backView.bringToFront();
}
else {
frontView.bringToFront();
}
flag = !flag;
}
}
and the corresponding layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/FrontView"
android:src="#drawable/front"
/>
<ImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/BackView"
android:src="#drawable/back"
/>
</RelativeLayout>
Maybe it's the layout I'm using? I'm not sure... I've tried FrameLayout and LinearLayout as well.

I would try swapping content views instead of ImageViews.
Put each imageView in a different layout and then it is easy:
public void onClick(View v) {
if (!flag) {
setContentView(R.layout.main_front);
frontView = (ImageView) findViewById(com.example.R.id.FrontView);
frontView.setOnClickListener(this);
}
else {
setContentView(R.layout.main_back);
backView = (ImageView) findViewById(com.example.R.id.BackView);
backView.setOnClickListener(this);
}
flag = !flag;
}

There are a couple of Components that you can use that do this for you.
ViewAnimator, ViewFlipper and ViewSwitcher. You can set the animations you require etc and they hand the rest.
here's one example.
http://www.androidpeople.com/android-viewflipper-example/
Given your example, do you have to call invalidate() on the parent after you've called bringToFront() ?