Develop Reference

I want to display the image view at different position on the screen randomly

Here the ImageView is displaying only at one position, after closing the activity the next time the activity is opened the ImageView will be on another position... I want to display the ImageView randomly at diff position on the same activity itself. The image view should appear on one point suddenly the next second ImageView should disappear from that position and appear on the next position. How can i do it?
public class page2 extends ActionBarActivity {
ImageView b2;
int count = 0;
Handler handler = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_page2);
Intent c = getIntent();
String name = c.getStringExtra("t");
Toast.makeText(getApplicationContext(), name, Toast.LENGTH_SHORT).show();
b2 = (ImageView) findViewById(R.id.redball);
AbsoluteLayout.LayoutParams absParams =
(AbsoluteLayout.LayoutParams)b2.getLayoutParams();
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int width = displaymetrics.widthPixels;
int height = displaymetrics.heightPixels;
Random r = new Random();
absParams.x = r.nextInt(width ) ;
absParams.y = r.nextInt(height );
b2.setLayoutParams(absParams);
Animation animation = AnimationUtils.loadAnimation(page2.this, R.anim.fade);
// Animation animation1 = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.activity_move);
b2.startAnimation(animation);
// b2.startAnimation(animation1);
b2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
count = count + 1;
}
});
handler = new Handler();
final Runnable t = new Runnable() {
public void run() {
Intent d = new Intent(getApplicationContext(), Page3.class);
d.putExtra("count", count);
d.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(d);
}
};
handler.postDelayed(t, 4000);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_page2, menu);
return true;
}

Don't use AbsoluteLayout, Why not use a custom view draw it?

You can achieve this by using Imageview within FrameLayout. Just change the layoutParams of the image to change its position.

As I understand it, you want that each time the activity is opened, so f you dont want to actually view to the user that the ImageView moves, why are you using Animation? You may just dynamically add the ImageView to the activity each time, and each time assign it different Margin attributes.
LinearLayout layout = (LinearLayout) view.findViewById(R.id.linear);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT);
params.setMargins(0, 0, 10, 0); //substitute parameters for left, top, right, bottom
ImageView iv = new ImageView(getActivity());
iv.setLayoutParams(params);
iv.setImageResource(R.drawable.yourimage);
layout.addView(iv);

for calucation
ContainerHeight = blinkerContainer.getHeight(); // total height of screen
ContainerWidth = blinkerContainer.getWidth(); //total width
blinkerHeight = blinkView.getHeight();
blinkerWidth = blinkView.getWidth();
minTopMargin = 30;
minLeftMargin = 30;
maxTopMargin = ContainerHeight - blinkerHeight - 30;
maxLeftMargin = ContainerWidth - blinkerWidth - 30;
for positioning
LinearLayout.LayoutParams params = (android.widget.LinearLayout.LayoutParams) blinkView
.getLayoutParams();
params.leftMargin = minLeftMargin
+ new Random().nextInt(maxLeftMargin - minLeftMargin);
params.topMargin = minTopMargin
+ new Random().nextInt(maxTopMargin - minTopMargin);
and you can use AlaramManager for Scheduling

Your solution is almost correct. Unfortunately, it looks like you're restarting the activity from your timer. Instead, you should just trigger the redraw.
This question has a couple of solutions on how to create a recurring timer. The solution with runOnUiThread() should allow you to execute the randomisation and re-displaying of the ImageView.

Android GridLayout only shows last child

I am new to Android Development. I have been working with using a GridLayout to display Dynamically inserted ImageViews.
My issue is located in "onFocusWindowChanged" but I pasted my onCreate where I do my assignments of the images.
private List<Behavior> behaviors = null;
private static int NUM_OF_COLUMNS = 2;
private List<ImageView> images;
private GridLayout grid;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_behaviors);
XMLPullParserHandler parser = new XMLPullParserHandler();
try {
behaviors = parser.parse(getAssets().open("catagories.xml"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
grid = (GridLayout) findViewById(R.id.behaviorGrid);
images = new ArrayList<ImageView>();
grid.setColumnCount(NUM_OF_COLUMNS);
grid.setRowCount(behaviors.size() / NUM_OF_COLUMNS);
for (Behavior behavior : behaviors)
images.add(this.getImageViewFromName(behavior.getName()));
}
#Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
View view = (View) findViewById(R.id.scrollView);
int width = (int) (view.getWidth() * .45);
Log.i("ViewWidth", Integer.toString(width));
GridLayout.LayoutParams lp = new GridLayout.LayoutParams();
lp.height = width;
lp.width = width;
int childCount = images.size();
ImageView image;
for (int i = 0; i < childCount-1; i++) {
image = images.get(i);
image.setLayoutParams(lp);
grid.addView(image);
}
}
In my (short) previous experience, using
grid.add(View);
worked fine, but now I am only seeing the last child display only. Looking through the debugger I can see that the gridview is being populated with more than just the last element, as well as the last imageview.
Thank you for your help

you should create a GridLayout.LayoutParams for each ImageView:
for (int i = 0; i < childCount-1; i++) {
GridLayout.LayoutParams lp = new GridLayout.LayoutParams();
lp.height = width;
lp.width = width;
......
}
GridLayout.LayoutParams contains location information, e.g [column:2, row:3]. In your code, all ImageViews are set the same GridLayout.LayoutParams, so they are located in the same cell(overlapping each other).
When use LinearLayout.LayoutParams instead, there is no location information in it. GridLayout will create a new GridLayout.LayoutParams for each child view, so all ImageViews use their own different GridLayout.LayoutParams and location.
Wish this help. You can read the GridLayout.java and ViewGroup.java for more details.

So I solved my issue, although I'm not sure how-
GridLayout.LayoutParams lp = new GridLayout.LayoutParams();
changed to...
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(x,y);
made it work just as I wanted it. But I'm not sure why- If anyone could explain, please do :)

Android: add textview in a RelativeLayout in random position

I'm adding some textview in a RelativeLayout called "number_container", this is my code but i don't see nothing, the textviews are not added...
private void labelAnimation(){
TextView number = new TextView(getApplicationContext());
number.setGravity(Gravity.CENTER);
Typeface font = Typeface.createFromAsset(getAssets(), "fonts/Gang of Three.ttf");
number.setTypeface(font);
Random random = new Random();
int random_size = random.nextInt(170 - 30) + 30;
number.setTextSize(random_size);
number.setTextColor(000000);
int random_text = random.nextInt(10-1)+1;
number.setText(Integer.toString(random_text));
int random_width = random.nextInt(width_screen - 50) + 50;
int random_height = random.nextInt(height_screen - 50) + 50;
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
lp.setMargins(random_width, random_height, 0, 0);
number.setLayoutParams(lp);
number_container.addView(number);
int random_delay = random.nextInt(800-100)+100;
final Handler animation_sun = new Handler();
animation_sun.postDelayed(new Runnable() {
#Override
public void run() {
labelAnimation();
}
}, random_delay);
}
I tried also to remove the custom font but no good results.
What can I do?

My problem was the color of the textView...
number.setTextColor(color.WHITE);

Android: How to make a gridview of equal proportions within the Java code

I am working on an application which has a main screen with a gridview layout.
As it stands currently, I am hardcoding in DP numbers for the height and width of the boxes, which I obviously do not want to do. How to I create code that will determine the users' screen size and match the boxes accordingly so that someone with a large phone like a note will view the same thing as someone on a droid mini? IE, when hardcoding to 500dp on each side, it looks like this:
But my goal is to make it look like this on every screen size:
Currently, this is the Java code I have:
public class ActivityAdapter extends BaseAdapter {
//Array of Icons that will be used as menu choices
public static int[] imageOptions = {
R.drawable.vacation_quota, //Position 0
R.drawable.revenue_deficit, //Position 1
//+ many more options...
};
private Context context;
//Constructor to pass context back to Main class
public ActivityAdapter(Context applicationContext) {
context = applicationContext;
}
//Number of elements to be displayed on the grid
#Override
public int getCount() {
return imageOptions.length;
}
#Override
public View getView(int position, View convertView, ViewGroup arg2) {
ImageView iv;
if(convertView != null){
iv = (ImageView) convertView;
} else {
iv = new ImageView(context);
//Here I have it hard coded to match a 480px width. Here is where I need to change it, just not sure how
iv.setLayoutParams(new GridView.LayoutParams(240, 240));
iv.setScaleType(ScaleType.CENTER_CROP); //Center the cropping
}
//Sets the image to correspond to its position within the array.
iv.setImageResource(imageOptions[position]);
return iv;
}
Any ideas? I think logically I want to figure out the screen dimensions and use them to make the image dimensions match, just not sure how. Research from other threads has not helped a great deal so hoping I can get a simpler answer here with code posting.

You should get the screen width and height. Then use these values to dynamically set height and width for each cell

Try this code-
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle state) {
setContentView(new ViewGroup(this) {
private RelativeLayout[] items = new RelativeLayout[9];
private int width, height, itemWidth, itemHeight;
{
Random r = new Random();
for (int i = 0; i < 9; i++) {
items[i] = new RelativeLayout(getContext());
float[] hsv = new float[] {360 * r.nextFloat(), .50f, .75f};
items[i].setBackgroundColor(Color.HSVToColor(hsv));
addView(items[i]);
// UPDATE ////////////////////////////////////
ImageView image = new ImageView(getContext());
switch (i) {
case 0: // top left
case 1: // top center
case 2: // top right
case 3: // center left
case 4: // center center
case 5: // center right
case 6: // bottom left
case 7: // bottom center
case 8: // bottom right
image.setImageResource(R.drawable.ic_launcher);
break;
}
image.setScaleType(ScaleType.FIT_XY);
image.setLayoutParams(new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT
));
items[i].addView(image);
//////////////////////////////////////////////
}
}
#Override
protected void onMeasure(int wMS, int hMS) {
width = MeasureSpec.getSize(wMS);
height = MeasureSpec.getSize(hMS);
itemWidth = width / 3;
itemHeight = height / 3;
wMS = MeasureSpec.makeMeasureSpec(itemWidth, MeasureSpec.EXACTLY);
hMS = MeasureSpec.makeMeasureSpec(itemHeight, MeasureSpec.EXACTLY);
measureChildren(wMS, hMS);
setMeasuredDimension(width, height);
}
#Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
for (int i = 0; i < 9; i++) {
l = itemWidth * (i % 3);
t = itemHeight * (i / 3);
r = l + itemWidth;
b = t + itemHeight;
items[i].layout(l, t, r, b);
}
}
});
super.onCreate(state);
}
}
Output-
Edit-
For creating scrollable grid view see this http://www.androidhive.info/2012/02/android-gridview-layout-tutorial/

I ended up not able to use some of the recommendations here and had to use a deprecated method to retain my app structure. The code specifically that was added to mine was:
iv = new ImageView(context);
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
float width2 = display.getWidth();
int length = (int) (width2/2);
iv.setLayoutParams(new GridView.LayoutParams(length, length));
With this, the height and width would crop to the right size depending on the size of the screen.

Android get programmatically created view's width

I have TextView created programmatically, like that:
TextView mTextView = new TextView(getApplicationContext());
final LayoutParams params = new TableLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
((MarginLayoutParams) params).setMargins(8, 8, 0, 0);
mTextView.setText(mText);
mTextView.setLayoutParams(params);
mTextView.setPadding(2, 2, 2, 2);
mTextView.setBackground(getResources().getDrawable(R.drawable.note_corps));
tagMap.addView(mTextView);
textViewsWidth = mTextView.getWidth();
But mTextView.getWidth() always returns 0
And if I try:
mTextView.getLayoutParams().width
It returns the LayoutParams corresponding value in the LayoutParams class (-1 or -2)
How can I get the view's width ?
EDIT I need to do this here:
#Override
public void onPostExecute(Hashtable<String, Integer> hash){
final ScrollView tagMapScroll = (ScrollView) findViewById(R.id.tagMapScroll);
final LinearLayout tagMap = (LinearLayout) findViewById(R.id.tagMap);
final ArrayList<Integer> arr = new ArrayList<Integer>(hash.values());
final Enumeration<String> e = hash.keys();
int index = 0;
int textViewsWidth = 0;
while(e.hasMoreElements()){
final TextView tV = new TextView(getApplicationContext());
tV.setTextColor(Color.parseColor("#666666"));
tV.setText(Html.fromHtml(randomColor() + e.nextElement()));
tV.setTextSize(arr.get(index));
final LayoutParams params = new TableLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
((MarginLayoutParams) params).setMargins(8, 8, 0, 0);
tV.setLayoutParams(params);
tV.setPadding(2, 2, 2, 2);
tV.setBackground(getResources().getDrawable(R.drawable.note_corps));
tagMap.addView(tV);
textViewsWidth += tV.getWidth();
index++;
}
tagMapScroll.setVisibility(ScrollView.VISIBLE);
}
EDIT SOLUTION I used this from #androiduser's answer:
mTextView.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int width = mTextView.getMeasuredWidth();
int height = mTextView.getMeasuredHeight();
Problem solved !

I used this solution:
yourView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
// Ensure you call it only once
yourView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
// Here you can get the size :)
}
});

get this way:
tV.post(new Runnable() {
#Override
public void run() {
int width=tV.getMeasuredWidth();
}
});

those values are constant value for FILL_PARENT and WRAP_CONTENT. If you want to check the view size you can try this way:
tagMap.addView(mTextView);
tagMap.post(new Runnable() {
#Override
public void run() {
mTextView. getWidth();
}
});
you have to wait until android draws the TextView. This way you are posting a Runnable in the tagMap queue, that is executed, hopefully after the textview is draw (so it should be weight and height)

In this method you can get the width height of the view..
#Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
int width = mTextView.getWidth();
int height = mTextView.getHeight();
}
and define TextView mTextView as global

You have to use ViewTreeObserver class which is used to register listeners that can be notified of global changes in the view tree. Such global events include, but are not limited to, layout of the whole tree, beginning of the drawing pass, touch mode change.
In the Activity's onCreate mehotd put this:
ViewTreeObserver vto = mTextView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
mTextView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
int viewWidth = mTextView.getMeasuredWidth();
}
});