Android : ScreenSize Support for 8 and 7 inch screen

Question

I have a problem which I`m unable to solve lately..

I have make a simple app for tablet which I run in my Samsung Galaxy Note 8.0 .. I have set the layout to place some text view at some place.. I code it in xml using dp for margin and sp for text size. The width and height layout is set to wrapcontent. But when I run it in my friend Samsung Galaxy Tab 2 7.0, the layout did not match what I see in my device. The same thing happen when I try to run it in 10inch emulator.

I have use layout-sw600dp for my layout folder..

Why my screen layout is like that?I though by using layout-sw600dp the layout supposedly to adjust itself.. Or am I wrong regarding that?

I have read android documentation regarding different screensize support and so far I found using layout-sw600dp is good solution..

I have checked the device dpi using :

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;

Answer 1

Every device has different pixel ratio, different dpi, different screen size and so on. Go to this link, read it, you will know how to manage different device layouts.

Android - Supporting Multiple Screen

Answer 2

If you want to check the screen inch size when the app start, you can calculate the inch with the following two methods, but I think the second one is more precisely.

public static float getScreenInchSizeByDensityDpi(Context context) {
    DisplayMetrics dm = context.getResources().getDisplayMetrics();
    double x = Math.pow((double)dm.widthPixels / (double)dm.densityDpi, 2);
    double y = Math.pow((double)dm.heightPixels / (double)dm.densityDpi, 2);
    double screenInches = Math.sqrt(x + y);

    return (float) screenInches;
}

public static float getScreenInchSizeByXYDpi(Context context) {
    DisplayMetrics dm = context.getResources().getDisplayMetrics();
    double x = Math.pow((double)dm.widthPixels / (double)dm.xdpi, 2);
    double y = Math.pow((double)dm.heightPixels / (double)dm.ydpi, 2);
    double screenInches = Math.sqrt(x + y);

    return (float) screenInches;
}