[url_launcher_android] Support intent:// URIs in launchUrl and canLaunchUrl

[sorou3h1]

Description

Fixes flutter/flutter#188068

url_launcher_android always constructs new Intent(Intent.ACTION_VIEW) for every URL, silently ignoring the action encoded in intent:// URIs. This means any call like:

await launchUrl(
  Uri.parse('intent://details?id=com.example.app'
    '#Intent;scheme=bazaar;package=com.example.store;action=android.intent.action.EDIT;end'),
  mode: LaunchMode.externalApplication,
);

…fires ACTION_VIEW instead of ACTION_EDIT, breaking the intent.

Fix

Detect intent:// URLs in both canLaunchUrl and launchUrl and delegate to Intent.parseUri(url, Intent.URI_INTENT_SCHEME), which is exactly how Android browsers handle this URI scheme. Non-intent:// URLs take the existing ACTION_VIEW path unchanged.

Tests

Added 4 tests to UrlLauncherTest:

• canLaunch_parsesIntentSchemeUri — verifies action, data URI, and package are correctly extracted
• canLaunch_returnsFalseForMalformedIntentSchemeUri — verifies URISyntaxException returns false
• launch_parsesIntentSchemeUri — same as above for launchUrl
• launch_returnsFalseForMalformedIntentSchemeUri

Related issue

flutter/flutter#188068

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[gemini-code-assist]

Code Review

This pull request adds support for parsing and launching intent:// URIs in canLaunchUrl and launchUrl within the Android implementation of url_launcher, along with corresponding unit tests. The review feedback suggests improving the URI scheme matching to be case-insensitive and to support intent: URIs without double slashes using regionMatches. Additionally, the feedback notes that HTTP headers are currently ignored when launching intent URIs and recommends forwarding them.

[gemini-code-assist]

Using url.startsWith("intent://") only matches URIs starting with the exact lowercase prefix and containing //. However, Android intent URIs can start with intent: (without //) and are case-insensitive per RFC 3986. Using url.regionMatches(true, 0, "intent:", 0, 7) is more robust and correctly supports all valid intent URIs.

Suggested change

	Intent launchIntent;
	if (url.startsWith("intent://")) {
	try {
	launchIntent = Intent.parseUri(url, Intent.URI_INTENT_SCHEME);
	} catch (URISyntaxException e) {
	return false;
	}
	} else {
	launchIntent = new Intent(Intent.ACTION_VIEW);
	launchIntent.setData(Uri.parse(url));
	}
	Intent launchIntent;
	if (url.regionMatches(true, 0, "intent:", 0, 7)) {
	try {
	launchIntent = Intent.parseUri(url, Intent.URI_INTENT_SCHEME);
	} catch (URISyntaxException e) {
	return false;
	}
	} else {
	launchIntent = new Intent(Intent.ACTION_VIEW);
	launchIntent.setData(Uri.parse(url));
	}

[gemini-code-assist]

This implementation has two issues:

1. It only matches intent:// URIs (case-sensitively). It should support any valid intent: URI case-insensitively.
2. It silently ignores the passed headers when launching an intent: URI. Even for intent URIs, we should preserve and attach the headers so that if the intent resolves to a browser or an app that handles HTTP headers, they are correctly forwarded.

We can fix both issues by using regionMatches and applying the headers to the resulting intent regardless of the scheme.

    Intent launchIntent;
    if (url.regionMatches(true, 0, "intent:", 0, 7)) {
      try {
        launchIntent = Intent.parseUri(url, Intent.URI_INTENT_SCHEME);
      } catch (URISyntaxException e) {
        return false;
      }
    } else {
      launchIntent = new Intent(Intent.ACTION_VIEW).setData(Uri.parse(url));
    }
    launchIntent.putExtra(Browser.EXTRA_HEADERS, extractBundle(headers));

[stuartmorgan-g]

Thanks for the contribution!

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