Develop Reference

How do I display an unknown number of RelativeLayouts?

I have an activity that should display X RelativeLayouts, where X is the length of a JSON array. How can I do this?
So far, I have tried this:
RelativeLayout[] interestLayouts = new RelativeLayout[jarr.length()];
for (int interest = 0; interest < jarr.length(); interest++) {
interestLayouts[interest] = (RelativeLayout) view.findViewById(R.id.X); // I don't know how to determine X
}

You can add the Relative Layout dynamically.
Linear LAYOUT; // suppose this is the layout where you want to add relativelayout
for (int i =0;i < jsonarray.length; i++){
Relative rLayout = new RelativeLayout(this);
LAYOUT.addView(rLayout);
}
something like this

Android - How to get a view's x and y coordinates into a gridLayout?

the actual wondering is the following : I have a full-screen GridLayout which has half of it visible. To see the second part we have to scroll.
I tried some ways and looked around for answers but none of whichs I found gave me what I need. In my grid there are square cells and each one contains a view, and I need to get the x and the y of these views.
Problem is that I could get the coordinates of the views that were put into the visible cells, the views that are not displayed have a x and a y set to 0... Whereas they were drawn..
Here it is, hope some of you guys could help! :)
private void createGrid(){
//I call the function several times
int gridsLength = 19*48*grids;
for(int i = 0; i < 19; i++) {
for (int j = 0; j < 48; j++) {
GridLayout.LayoutParams layoutParams = new GridLayout.LayoutParams();
layoutParams.width = 40;
layoutParams.height = 40;
View view = new View(this);
view.setLayoutParams(layoutParams);
Util.setDrawableBackground(view, R.drawable.border_black, this);
view.setOnTouchListener(newViewListener());
gridViews.add(view);
//glMain is my gridLayout that i put into global variable
glMain.addView(view, i + j + gridsLength);
}
}
grids++;
}

EDIT : I finally found out that I was not always accessing the views AFTER the grid were drawn so I changed that and it's working... Figured out that I was just a fool ^^

How to set icon size in TabLayout?

Here is my code:
private TabLayout tabLayout;
private int[] tabIcons = {
R.mipmap.ic_compass,
R.mipmap.ic_place,
R.mipmap.ic_passport,
R.mipmap.ic_setting
};
...
tabLayout.getTabAt(0).setIcon(tabIcons[0]);
tabLayout.getTabAt(1).setIcon(tabIcons[1]);
tabLayout.getTabAt(2).setIcon(tabIcons[2]);
tabLayout.getTabAt(3).setIcon(tabIcons[3]);
The size of icon is according to image size. How could I resize it?

set icons padding
for (int i = 0; i < tablayout.getTabWidget().getChildCount(); i++)
{
tablayout.getTabWidget().getChildAt(i).setPadding(10,10,10,10);
}

If you don't want to use xml for the custom view. Simply create imageview on runtime and add that in tablayout in a particular tab.
ImageView imgView= new ImageView(MainActivity.this);
imgView.setImageResource(drawableImage);
imgView.setPadding(10,10,10,10)
tabLayout.getTabAt(1).setCustomView(imgView);
It will look like this.

change of Icon size android.support.design.widget.TabLayout
for (int i = 0; i < view_bottom_tabLayout.getTabCount(); i++)
{
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(60, 60); //set new width & Height
params.gravity = Gravity.CENTER; //set gravity back to center
view_bottom_tabLayout.getChildAt(i).setLayoutParams(params);//set ur new params
}

To get total control of size I recommend using a custom view to render the tab.
First create a new layout - named "my_custom_tab" for this example
<?xml version="1.0" encoding="utf-8"?>
<!--Change the width, height, scaleType to whatever you like-->
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scaleType="fitCenter"
android:id="#+id/icon"
android:layout_gravity="center_horizontal"
android:src="#mipmap/ic_launcher"/>
Now in your code set the custom image
private void setUpTabs (ViewPager viewPager) {
TabLayout tabs = (TabLayout) findViewById(R.id.tabs);
if (tabs != null) {
tabs.setupWithViewPager(viewPager);
int tabCount = tabAdapter.getCount(); //Assuming you have already somewhere set the adapter for the ViewPager
for (int i = 0; i < tabCount; i++) {
TabLayout.Tab tab = tabs.getTabAt(i);
if (tab != null){
ImageView myCustomIcon = (ImageView) LayoutInflater.from(tabs.getContext()).inflate(R.layout.my_custom_tab, null);
/*Here is where to set image if doing it dynamically
myCustomIcon.setImageBitmap(bitmap);
*/
tab.setCustomView(myCustomIcon);
}
}
}
}

you can do this:
LinearLayout ll = (LinearLayout) tabLayout.getChildAt(0);
for (int i = 0; i < ll.getChildCount(); i++) {
LinearLayout tabView = (LinearLayout) ll.getChildAt(i);
for (int j = 0; j < tabView.getChildCount(); j++) {
if (tabView.getChildAt(j) instanceof TextView) {
TextView textView = (TextView) tabView.getChildAt(j);
LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) textView.getLayoutParams();
layoutParams.topMargin = 0;
textView.setLayoutParams(layoutParams);
} else if (tabView.getChildAt(j) instanceof ImageView) {
ImageView imageView = (ImageView) tabView.getChildAt(j);
LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) imageView.getLayoutParams();
layoutParams.bottomMargin = 0;
imageView.setLayoutParams(layoutParams);
}
}
}

I decide to close this question. Since we actually cannot set specific size for icon in TabLayout but padding to it.
Ref:
https://developer.android.com/guide/practices/ui_guidelines/icon_design_tab

one code worked for me, the answer above of Deepak Sachdeva
just i edited it a litlle, try it 100% working
from first i add the tab with custom image
ImageView imgView= new ImageView(getApplicationContext());
imgView.setImageResource(R.drawable.icon);
imgView.setScaleType(ImageView.ScaleType.FIT_CENTER);
imgView.setLayoutParams(new LinearLayout.LayoutParams(100, 100));
tablayout1.addTab(tablayout1.newTab().setCustomView(imgView));
and do that to all your tabs, add them by this way.

How to change the color of programmatically added buttons?

I recently started making a chess-like game for android. The first thing I needed was to make the 8 by 8 board. I figured adding 64 buttons and organizing them in the XML wouldn't be much efficient, so I found a way to create them programmatically using a simple 8x8 matrix of buttons. Until this point, everything worked as intended, and I had this:
The next thing I tried was to change the colors of the buttons to match a chessboard. On the internet I found some ways of doing it, but pretty much all of them just made my buttons invisible, and did not change their color.
Here's the onCreate method (the only thing I modified so far):
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_menu);
//GETTING SCREEN DIMENSIONS
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
//SETTING THE BOARD
int TILESIZE = width/8;
LinearLayout back = (LinearLayout) findViewById(R.id.back);
LinearLayout[] rows = new LinearLayout[8];
Button[][] tiles = new Button[8][8];
for(int i = 0; i < 8; i++){
rows[i] = new LinearLayout(this);
back.addView(rows[i]);
for(int j = 0; j < 8; j++){
tiles[i][j] = new Button(this);
tiles[i][j].setWidth(TILESIZE);
tiles[i][j].setHeight(tiles[i][j].getWidth());
if((i + j) % 2 == 0){
tiles[i][j].setBackgroundColor(0xFFFFFFFF);
tiles[i][j].invalidate();
}
else{
//TODO: Make tiles black
}
rows[i].addView(tiles[i][j]);
}
}
}
The XML file contains a single vertical linear layout called back.
My question is how can I make the buttons change color, and where am I doing something wrong. I would also gladly accept alternative (or better) ways to make the board.

Change your loop like this and try
for(int i = 0; i < 8; i++){
rows[i] = new LinearLayout(this);
for(int j = 0; j < 8; j++){
tiles[i][j] = new Button(this);
tiles[i][j].setWidth(TILESIZE);
tiles[i][j].setHeight(tiles[i][j].getWidth());
if((i + j) % 2 == 0){
tiles[i][j].setBackgroundColor(0xFFFFFFFF);
tiles[i][j].invalidate();
}
else{
//TODO: Make tiles black
}
rows[i].addView(tiles[i][j]);
}
back.addView(rows[i]);
}

Change your if loop like this:
if((i + j) % 2 == 0)
tiles[i][j].setBackgroundColor(android.R.color.holo_blue_dark);
else
tiles[i][j].setBackgroundColor(android.R.color.holo_red_dark);
You can define black and white colors in your color.xml file and add them instead using tiles[i][j].setBackgroundColor(getResources().getColor(R.color.white)); and similarly for black.
But make sure, you use a different background so they are clearly visible.

How to align tab text at center in android

Can anybody tell me how to align tab text in the center in android? I had given android:gravity="center" for LinearLayout and TabWidget. It is still not working. Can anybody tell me how to do this?
Thanks

use this
int tabCount = tabHost.getTabWidget().getTabCount();
for (int i = 0; i < tabCount; i++) {
final View view = tabHost.getTabWidget().getChildTabViewAt(i);
if ( view != null ) {
// reduce height of the tab
view.getLayoutParams().height *= 0.66;
// get title text view
final View textView = view.findViewById(android.R.id.title);
if ( textView instanceof TextView ) {
// just in case check the type
// center text
((TextView) textView).setGravity(Gravity.CENTER);
// wrap text
((TextView) textView).setSingleLine(false);
// explicitly set layout parameters
textView.getLayoutParams().height = ViewGroup.LayoutParams.FILL_PARENT;
textView.getLayoutParams().width = ViewGroup.LayoutParams.WRAP_CONTENT;
}
}
}

Use android:layout_gravity="center"