Develop Reference

Changing text size according to the change in the button size

I have a toggle button that changes it's size as following :
protected int[] calculateCardWidth(int[] rowsCols) {
//Getting the screen size.
Display display = this.getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
//cardWidHigh 0->width , 1 ->height.
cardWidHigh[0] = (int) (width / (rowsCols[1] + .25));
cardWidHigh[1] = (int) (height / (rowsCols[0] + 2));
return cardWidHigh;
}
I want to be able to change the text size according to the change in button size (it's width and height )dynamically, what is the best approach inorder to achieve this ?

You change the values of its LayoutParams, the parent will use the new values to rerender the screen at new positions:
LayoutParams p = cardView.getLayoutParams();
p.width = cardWidth[0];
p.height = cardWidth[1];
cardView.setLayoutParams(p);
cardView.getViewParent().invalidate();

android video frame does not fill screen on landscape

So I have this code, which is called onConfigurationChanged :
private void setVideoLayoutParams(){
LinearLayout.LayoutParams params;
if(getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT){
// this works as expected
showNavigationAndStatusBars();
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
params = new LinearLayout.LayoutParams(size.x, size.x * 9 / 16);
}else{
hideNavigationAndStatusBars();
// this does not work properly
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
params = new LinearLayout.LayoutParams(size.x, size.y);
}
controller.setPauseButtonSize();
Log.d(TAG, "video layout params set : " + params.width + "/" + params.height);
videoFrame.setLayoutParams(params);
}
private void hideNavigationAndStatusBars(){
View decorView = getWindow().getDecorView();
int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_FULLSCREEN;
decorView.setSystemUiVisibility(uiOptions);
}
private void showNavigationAndStatusBars(){
View decorView = getWindow().getDecorView();
int uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
decorView.setSystemUiVisibility(uiOptions);
}
When the screen is rotated into landscape, the navigation and status bars disappear. However my videoFrame does not fill the screen.
A small portion on the right side of the screen remains blank and is equal to height of the navigation bar.
Another small portion on the bottom of the screen equal to the height of the notification bar remains blank.
When the params are created, my logger shows 1794/1080. When I touch the screen, I log the size of the videoFrame and it shows 1794/1009. My guess is it should show, in both cases, 1800/1080.
What am I doing wrong?

Put your Videoview inside a Relative layout and add alignparentright, alignparentleft, alignparenttop and alignparentbottom "true". It will be perfect.

Your layout is like this right?
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<VideoView android:id="#+id/myvideoview"
android:layout_width="fill_parent"
android:layout_alignParentRight="true"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_alignParentBottom="true"
android:layout_height="fill_parent">
</VideoView>
</RelativeLayout>
And try
DisplayMetrics metrics = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(metrics);
android.widget.LinearLayout.LayoutParams params = (android.widget.LinearLayout.LayoutParams) videoView.getLayoutParams();
params.width = metrics.widthPixels;
params.height = metrics.heightPixels;
params.leftMargin = 0;
videoView.setLayoutParams(params);

Screen height - Android

In an Android Application, I want to know the height and the width of the screen. I'm using the following code:
Point size = new Point();
display.getSize(size);
screenWidth = size.x;
screenHeight = size.y;
The problem is than when the soft navigation bar exists, the returned height = the actual height - navigation bar height.
I want to get the total value.
Note: I'm using Android SDK 13 (v 3.2).

Check this, it may help:
FrameLayout root = (FrameLayout) findViewById(R.id.root);
root.post(new Runnable() {
public void run() {
Rect rect = new Rect();
Window win = getWindow(); // Get the Window
win.getDecorView().getWindowVisibleDisplayFrame(rect);
// Get the height of Status Bar
int statusBarHeight = rect.top;
// Get the height occupied by the decoration contents
int contentViewTop = win.findViewById(Window.ID_ANDROID_CONTENT).getTop();
// Calculate titleBarHeight by deducting statusBarHeight from contentViewTop
int titleBarHeight = contentViewTop - statusBarHeight;
// By now we got the height of titleBar & statusBar , Now lets get the screen size
int screenHeight = dm.heightPixels;
// Now calculate the height that our layout can be set If you know that your application doesn't have statusBar added, then don't add here also.
//Same applies to application bar also
int layoutHeight = screenHeight - (titleBarHeight + statusBarHeight);
}
});

You can use
display.getRealSize(size); instead of display.getSize(size);
source:
http://developer.android.com/reference/android/view/Display.html#getRealSize(android.graphics.Point)

you can use DisplayMetrics. This class holds information about the screen such its size, density, font scaling. For instance
getResources().getDisplayMetrics().widthPixels
returns
The absolute width of the display in pixels.
to retrieve the height
getResources().getDisplayMetrics().heightPixels

In onCreate method of your class write down this code, and you will get the actual width and height of screen:
Display mDisplay = this.getWindowManager().getDefaultDisplay();
final int width = mDisplay.getWidth();
final int height = mDisplay.getHeight();
System.out.println("width " + width + " height " + height);

Android how to programmatically create scrollview and add programmatically created views into it

Alright I'm trying to build an activity that has a horizontal scrollview, that the user can swipe through, to view different "pages". My train of thought is these "pages" will be views. The following is a mockup of my idea (to mess around to see if it works)
I've experimented with this as follows:
My content view is set to the the scrollview. (unsure if this is an incorrect approach)
I create the scrollview, and place a view into it as follows:
private void setupScrollView()
{
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics ();
display.getMetrics(outMetrics);
float density = getResources().getDisplayMetrics().density;
float dpHeight = outMetrics.heightPixels / density;
float dpWidth = outMetrics.widthPixels / density;
int width = (int)MeasureUtils.convertDpToPixel(dpWidth, getApplicationContext());
int height = (int)MeasureUtils.convertDpToPixel(dpHeight, getApplicationContext());
_scrollView = new HorizontalScrollView(getApplicationContext());
_scrollView.setBackgroundColor(Color.CYAN);
_scrollView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
Log.i("DEBUG", "Screen dp width = " + dpWidth + " screen dp height = " + dpHeight);
TextView view = new TextView(getApplicationContext());
view.setBackgroundColor(Color.RED);
view.setText("TEST");
view.setX(0); // Start at the left of the scrollview.
view.setWidth(width); // Size it so that it fills to the right of the scrollview.
TextView view2 = new TextView(getApplicationContext());
view2.setBackgroundColor(Color.GREEN);
view2.setText("TEST2");
view2.setX(width); // Start the second "page/view" offscreen to the right where i can scroll to it
view.setWidth(width); // Fill the screen width
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setBackgroundColor(Color.MAGENTA);
layout.addView(view);
layout.addView(view2);
_scrollView.addView(layout);
}
The idea above is that I will see a view, that takes up the screen, representing a page. This view should be "RED" in color. I can then scroll horizontally to the right and see the second view (view2) representing the next page. This view should be "GREEN" in color. This does not happen. I end up seeing what looks like 1/3rd or 1/2 of my screen being view1, the linearlayout taking up almost the whole screen (a bit of a gap to the right edge where the CYAN from the scrollview bleeds through).
Am I approaching this the wrong way, and/or is it possible to make this work the way I'm going at it?

You probably do not want to use a horizontalscroll view to create "pages".
Try looking at PageViewer
This automatically builds in all the sywpe and inflating logic for you.
Basically you will get a call to inflate a certain page. There you can then create your view (dynamically if you wish) and then just return the root to be rendered.

Alright I've figured out what I was doing wrong, and it turned out to be something very small...
The complete code is here:
private void setupScrollView()
{
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics ();
display.getMetrics(outMetrics);
float density = getResources().getDisplayMetrics().density;
float dpHeight = outMetrics.heightPixels / density;
float dpWidth = outMetrics.widthPixels / density;
int width = (int)MeasureUtils.convertDpToPixel(dpWidth, getApplicationContext());
int height = (int)MeasureUtils.convertDpToPixel(dpHeight, getApplicationContext());
_scrollView = new HorizontalScrollView(getApplicationContext());
_scrollView.setBackgroundColor(Color.CYAN);
_scrollView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
Log.i("DEBUG", "Screen dp width = " + dpWidth + " screen dp height = " + dpHeight);
TextView view = new TextView(getApplicationContext());
view.setBackgroundColor(Color.RED);
view.setText("TEST");
view.setX(0);
view.setWidth(width);
view.setHeight(height - 50);
TextView view2 = new TextView(getApplicationContext());
view2.setBackgroundColor(Color.GREEN);
view2.setText("TEST2");
view2.setX(0);
view2.setWidth(width);
view2.setHeight(height - 50);
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setBackgroundColor(Color.MAGENTA);
layout.addView(view);
layout.addView(view2);
_scrollView.addView(layout);
}
This creates a horizontal scrollview programmatically, as I had, but the problem was that I was setting the second view to be "width" away, when it should be set to "0"as can be seen by:
view2.setX(0);
With that, I get 2 "views" that resemble pages in my scrollview that I can swipe through. Each taking up the whole page.
Hate having the code close and it being a simple fix that I missed :|
Hope this helps anyone else that tries to do it this way. I'm going to look into the PageViewer as Frank suggested.

Android: Get Screen size for the root Layout only

Please get me correctly over here :
I want to get the height/width of the space available to the Activity/Layout in onCreate() method to calculate the height that can be given to child layouts. I can get the screen size using :
root = (LinearLayout) findViewById(R.id.mainroot); // Main layout of LinearLayout
android.view.Display display = getWindowManager().getDefaultDisplay();
int height = Display.getHeight(); // I know this is deprecated have hence used
int width = Display.getWidth(); // DisplayMetrics
int childWidth, childHeight;
DisplayMetrics metrics = new DisplayMetrics();
display.getMetrics(metrics);
//int density = metrics.densityDpi;
height = metrics.heightPixels; //480
width = metrics.widthPixels; //320
This both the methods/ways gives me same height and width i.e. size of full screen. What I am looking for is to get actual height that is avaialbe for the layout after deduction of Application Title, Status Bar, etc.
Any idea how to get this. OR to get the sizes of titles, etc - what all should be counted over here. On emulator I see 2 bars on top - 1 must be application titile what an be the other one. I can get heights of them all and deduct from screen height.
ONE more point : In this case I will be setting the height programamtically so it will be pixel based (as I can setheight in pixels only I guess) will that affect in density factor with differnet screen sizes. What can be a way to calculate height (lets say 50%) for child layout that will be same for any density o so.

SOLUTION :
In my onCreate(), I added the following lines :
setContentView(R.layout.mainpage);
root = (LinearLayout) findViewById(R.id.mainroot);
root.post(new Runnable() {
public void run() {
Rect rect = new Rect();
Window win = getWindow();
win.getDecorView().getWindowVisibleDisplayFrame(rect);
int statusHeight = rect.top;
int contentViewTop = win.findViewById(Window.ID_ANDROID_CONTENT).getTop();
titleHeight = contentViewTop - statusHeight;
Log.i(Utility.TAG, "titleHeight = " + titleHeight + " statusHeight = " + statusHeight + " contentViewTop = " + contentViewTop);
// CALCULATE THE SIZE OF INNER LAYOUTS
calculateChildSize();
}
});
With the above code, I get the values of titleBar & statusBar. On deducting it from metrics.heightPixels; I get the required height of the screen.
Good Point is this code works for all density's.
Hope this helps others too.
FOR IMPROVEMENT : I have to do similar calculations for all Activities in my application, so was thinking about writing this code only once. I can save teh titleHeight to a static variable so can use in all activities.
BUT
Can the user change the phone's density at runtime.
If so, then the Activity's onCreate will be called again or not ?
If not, then can I trap the density change event where I can add this code and make the current activity to refresh.
Any idea suggestions for improving is appreciated.

//Where rootView is the object for the root view of your application
final int viewWidt = rootView.getMeasuredWidth();

There is very easy method for that. doOnLayout() method is called as soon as layout is measured and ready:
rootView.doOnLayout {
rootView.getMeasuredWidth()
rootView.getMeasuredHeight()
}