How can I make my app visible to implicit intents to open a PDF file?

Issue

I want to create a simple app that can view PDF files.

To test that I have deleted the default PDF file viewer on the emulator and when I want to open a PDF file the emulator says Can't open that file.

How can I make my app visible to that implicit intent so it will be used/shown when I click that PDF file?
What <intent-filter> configuration do I need to add in my manifest.xml, if any?

Solution

@see javdromero's post

javdromero's approach worked for me after making a few tweaks.

1. Specify the PDF mime type

The mime type for PDF files is application/pdf so we have to use that:

android:mimeType="application/pdf"

The android:host attribute can be ignored because we don't take anything from the web and don't have the android:scheme attribute specified. The same goes for the android:pathPattern attribute. See the <data> element's documentation.

That leaves us with an error message Missing URL and the text is in red.

2. Ignore the Missing URL error

The Missing URL error concerns the whole <intent-filter> element because we should specify the android:scheme attribute there.
But we don't use any schemes so we import the tools namespace and specify the tools:ignore attribute:

tools:ignore="AppLinkError"

That leaves us with following <intent-filter> element configuration:

<intent-filter tools:ignore="AppLinkUrlError">
    <action android:name="android.intent.action.VIEW"/>

    <category android:name="android.intent.category.DEFAULT"/>

    <data android:mimeType="application/pdf" />
</intent-filter>

Answered By - René Jörg Spies