Android M Permissions : Confused on the usage of shouldShowRequestPermissionRationale() function

androidandroid-6.0-marshmallowpermissions

I was going through the official doc about the new Permissions model in Android M. It talks about the shouldShowRequestPermissionRationale() function which returns true if the app has requested this permission previously and the user denied the request. If the user turned down the permission request in the past and chose the Don't ask again option, this method returns false.

But how can we differentiate between the following two cases?

Case 1: The app doesn't have a permission and the user has not been asked for the permission before. In this case, shouldShowRequestPermissionRationale() will return false because this is the first time we're asking the user.

Case 2: The user has denied the permission and selected "Don't ask again", in this case too shouldShowRequestPermissionRationale() will return false.

I would want to send the user to the App's settings page in Case 2. How do i go about differentiating these two cases?

Best Answer

After M Preview 1, if the dialog is displayed for the first time, there is no Never ask again checkbox.

If the user denies the permission request, there will be a Never ask again checkbox in the permission dialog the second time permission is requested.

So the logic should be like this:

Request permission:

if (ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
    ActivityCompat.requestPermissions(context, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE);
} else {
    //Do the stuff that requires permission...
}

Check if the permission was denied or granted in onRequestPermissionsResult.

If the permission was denied previously, this time there will be a Never ask again checkbox in the permission dialog.

Call shouldShowRequestPermissionRationale to see if the user checked Never ask again. shouldShowRequestPermissionRationale method returns false only if the user selected Never ask again or device policy prohibits the app from having that permission:

if (grantResults.length > 0){
    if(grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        //Do the stuff that requires permission...
    }else if (grantResults[0] == PackageManager.PERMISSION_DENIED){
        // Should we show an explanation?
        if (ActivityCompat.shouldShowRequestPermissionRationale(context, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            //Show permission explanation dialog...
        }else{
            //Never ask again selected, or device policy prohibits the app from having that permission.
            //So, disable that feature, or fall back to another situation...
        }
    }
}

So, you won't have to track if a user checked Never ask again or not.

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Android – How to close/hide the Android soft keyboard programmatically

You can force Android to hide the virtual keyboard using the InputMethodManager, calling hideSoftInputFromWindow, passing in the token of the window containing your focused view.

// Check if no view has focus:
View view = this.getCurrentFocus();
if (view != null) {  
    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
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This will force the keyboard to be hidden in all situations. In some cases, you will want to pass in InputMethodManager.HIDE_IMPLICIT_ONLY as the second parameter to ensure you only hide the keyboard when the user didn't explicitly force it to appear (by holding down the menu).

Note: If you want to do this in Kotlin, use: context?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager

Kotlin Syntax

// Only runs if there is a view that is currently focused
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Android – the difference between “px”, “dip”, “dp” and “sp”

From the Android Developer Documentation:

px
> Pixels - corresponds to actual pixels on the screen.
in
> Inches - based on the physical size of the screen.
> 1 Inch = 2.54 centimeters
mm
> Millimeters - based on the physical size of the screen.
pt
> Points - 1/72 of an inch based on the physical size of the screen.
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> Density-independent Pixels - an abstract unit that is based on the physical density of the screen. These units are relative to a 160 dpi screen, so one dp is one pixel on a 160 dpi screen. The ratio of dp-to-pixel will change with the screen density, but not necessarily in direct proportion. Note: The compiler accepts both "dip" and "dp", though "dp" is more consistent with "sp".
sp
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From Understanding Density Independence In Android:

Density Bucket	Screen Density	Physical Size	Pixel Size
ldpi	120 dpi	0.5 x 0.5 in	0.5 in * 120 dpi = 60x60 px
mdpi	160 dpi	0.5 x 0.5 in	0.5 in * 160 dpi = 80x80 px
hdpi	240 dpi	0.5 x 0.5 in	0.5 in * 240 dpi = 120x120 px
xhdpi	320 dpi	0.5 x 0.5 in	0.5 in * 320 dpi = 160x160 px
xxhdpi	480 dpi	0.5 x 0.5 in	0.5 in * 480 dpi = 240x240 px
xxxhdpi	640 dpi	0.5 x 0.5 in	0.5 in * 640 dpi = 320x320 px

Unit	Description	Units Per Physical Inch	Density Independent?	Same Physical Size On Every Screen?
px	Pixels	Varies	No	No
in	Inches	1	Yes	Yes
mm	Millimeters	25.4	Yes	Yes
pt	Points	72	Yes	Yes
dp	Density Independent Pixels	~160	Yes	No
sp	Scale Independent Pixels	~160	Yes	No

More info can be also be found in the Google Design Documentation.

Best Answer

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