Check if calendar add-on is available. Fixes #1017

2 files changed, 44 insertions, 14 deletions

diff --git a/main/src/cgeo/geocaching/CacheDetailActivity.java b/main/src/cgeo/geocaching/CacheDetailActivity.java
index 8cea884..9a7b60c 100644
--- a/main/src/cgeo/geocaching/CacheDetailActivity.java
+++ b/main/src/cgeo/geocaching/CacheDetailActivity.java
@@ -723,20 +723,25 @@ public class CacheDetailActivity extends AbstractActivity {
     }
 
     private void addToCalendarWithIntent() {
-        // this method is NOT unused :)
-        final Parameters params = new Parameters(
-                ICalendar.PARAM_NAME, cache.getName(),
-                ICalendar.PARAM_NOTE, StringUtils.defaultString(cache.getPersonalNote()),
-                ICalendar.PARAM_HIDDEN_DATE, String.valueOf(cache.getHiddenDate().getTime()),
-                ICalendar.PARAM_URL, StringUtils.defaultString(cache.getUrl()),
-                ICalendar.PARAM_COORDS, cache.getCoords() == null ? "" : cache.getCoords().format(GeopointFormatter.Format.LAT_LON_DECMINUTE_RAW),
-                ICalendar.PARAM_LOCATION, StringUtils.defaultString(cache.getLocation()),
-                ICalendar.PARAM_SHORT_DESC, StringUtils.defaultString(cache.getShortDescription())
-                );
-
-        // TODO: Check if addon is installed, if not, tell the user how to get it.
-        startActivity(new Intent(ICalendar.INTENT,
-                Uri.parse(ICalendar.URI_SCHEME + "://" + ICalendar.URI_HOST + "?" + params.toString())));
+
+        final boolean calendarAddOnAvailable = cgBase.isIntentAvailable(this, ICalendar.INTENT);
+
+        if (calendarAddOnAvailable) {
+            final Parameters params = new Parameters(
+                    ICalendar.PARAM_NAME, cache.getName(),
+                    ICalendar.PARAM_NOTE, StringUtils.defaultString(cache.getPersonalNote()),
+                    ICalendar.PARAM_HIDDEN_DATE, String.valueOf(cache.getHiddenDate().getTime()),
+                    ICalendar.PARAM_URL, StringUtils.defaultString(cache.getUrl()),
+                    ICalendar.PARAM_COORDS, cache.getCoords() == null ? "" : cache.getCoords().format(GeopointFormatter.Format.LAT_LON_DECMINUTE_RAW),
+                    ICalendar.PARAM_LOCATION, StringUtils.defaultString(cache.getLocation()),
+                    ICalendar.PARAM_SHORT_DESC, StringUtils.defaultString(cache.getShortDescription())
+                    );
+
+            startActivity(new Intent(ICalendar.INTENT,
+                    Uri.parse(ICalendar.URI_SCHEME + "://" + ICalendar.URI_HOST + "?" + params.toString())));
+        } else {
+            showToast(res.getString(R.string.helper_calendar_missing));
+        }
     }
 
     /**
diff --git a/main/src/cgeo/geocaching/cgBase.java b/main/src/cgeo/geocaching/cgBase.java
index 9cb9e22..c833317 100644
--- a/main/src/cgeo/geocaching/cgBase.java
+++ b/main/src/cgeo/geocaching/cgBase.java
@@ -61,6 +61,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
+import android.content.pm.ResolveInfo;
 import android.content.res.Resources;
 import android.graphics.drawable.BitmapDrawable;
 import android.net.Uri;
@@ -3116,5 +3117,29 @@ public class cgBase {
         cgBase.actualStatus = actualStatus;
     }
 
+    /**
+     * Indicates whether the specified action can be used as an intent. This
+     * method queries the package manager for installed packages that can
+     * respond to an intent with the specified action. If no suitable package is
+     * found, this method returns false.
+     *
+     * From: http://android-developers.blogspot.com/2009/01/can-i-use-this-intent.html
+     * 
+     * @param context
+     *            The application's environment.
+     * @param action
+     *            The Intent action to check for availability.
+     * 
+     * @return True if an Intent with the specified action can be sent and
+     *         responded to, false otherwise.
+     */
+    public static boolean isIntentAvailable(Context context, String action) {
+        final PackageManager packageManager = context.getPackageManager();
+        final Intent intent = new Intent(action);
+        List<ResolveInfo> list = packageManager.queryIntentActivities(intent,
+                PackageManager.MATCH_DEFAULT_ONLY);
+        return list.size() > 0;
+    }
+
 }