From 705dec0571d4ebc17efa4726c41631715ca59fa4 Mon Sep 17 00:00:00 2001
From: Dimitry Ivanov <mail@dimitryivanov.ru>
Date: Sat, 12 Jan 2019 16:13:15 +0300
Subject: [PATCH] Markwon.hasPlugin method

---
 .../main/java/ru/noties/markwon/Markwon.java  | 13 +++++++++
 .../java/ru/noties/markwon/MarkwonImpl.java   | 12 ++++++++
 .../ru/noties/markwon/MarkwonImplTest.java    | 28 +++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/markwon-core/src/main/java/ru/noties/markwon/Markwon.java b/markwon-core/src/main/java/ru/noties/markwon/Markwon.java
index bf963995..6e7e1ba3 100644
--- a/markwon-core/src/main/java/ru/noties/markwon/Markwon.java
+++ b/markwon-core/src/main/java/ru/noties/markwon/Markwon.java
@@ -88,6 +88,19 @@ public abstract class Markwon {
 
     public abstract void setParsedMarkdown(@NonNull TextView textView, @NonNull Spanned markdown);
 
+    /**
+     * Requests information if certain plugin has been registered. Please note that this
+     * method will check for super classes also, so if supplied with {@code markwon.hasPlugin(MarkwonPlugin.class)}
+     * this method (if has at least one plugin) will return true. If for example a custom
+     * (subclassed) version of a {@link CorePlugin} has been registered and given name
+     * {@code CorePlugin2}, then both {@code markwon.hasPlugin(CorePlugin2.class)} and
+     * {@code markwon.hasPlugin(CorePlugin.class)} will return true.
+     *
+     * @param plugin type to query
+     * @return true if a plugin is used when configuring this {@link Markwon} instance
+     */
+    public abstract boolean hasPlugin(@NonNull Class<? extends MarkwonPlugin> plugin);
+
     /**
      * Builder for {@link Markwon}.
      * <p>
diff --git a/markwon-core/src/main/java/ru/noties/markwon/MarkwonImpl.java b/markwon-core/src/main/java/ru/noties/markwon/MarkwonImpl.java
index 3cf105b5..8d5211d8 100644
--- a/markwon-core/src/main/java/ru/noties/markwon/MarkwonImpl.java
+++ b/markwon-core/src/main/java/ru/noties/markwon/MarkwonImpl.java
@@ -95,4 +95,16 @@ class MarkwonImpl extends Markwon {
             plugin.afterSetText(textView);
         }
     }
+
+    @Override
+    public boolean hasPlugin(@NonNull Class<? extends MarkwonPlugin> type) {
+        boolean result = false;
+        for (MarkwonPlugin plugin : plugins) {
+            if (type.isAssignableFrom(plugin.getClass())) {
+                result = true;
+                break;
+            }
+        }
+        return result;
+    }
 }
diff --git a/markwon-core/src/test/java/ru/noties/markwon/MarkwonImplTest.java b/markwon-core/src/test/java/ru/noties/markwon/MarkwonImplTest.java
index 62ab3de0..f0771efa 100644
--- a/markwon-core/src/test/java/ru/noties/markwon/MarkwonImplTest.java
+++ b/markwon-core/src/test/java/ru/noties/markwon/MarkwonImplTest.java
@@ -16,9 +16,11 @@ import org.robolectric.annotation.Config;
 
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
@@ -229,4 +231,30 @@ public class MarkwonImplTest {
 
         verify(plugin, times(1)).afterSetText(eq(textView));
     }
+
+    @Test
+    public void has_plugin() {
+
+        final class First extends AbstractMarkwonPlugin {
+        }
+
+        final class Second extends AbstractMarkwonPlugin {
+        }
+
+        final List<MarkwonPlugin> plugins = Collections.singletonList((MarkwonPlugin) new First());
+
+        final MarkwonImpl impl = new MarkwonImpl(
+                TextView.BufferType.SPANNABLE,
+                mock(Parser.class),
+                mock(MarkwonVisitor.class),
+                plugins);
+
+        assertTrue("First", impl.hasPlugin(First.class));
+        assertFalse("Second", impl.hasPlugin(Second.class));
+
+        // can use super types. So if we ask if CorePlugin is registered,
+        // but it was subclassed, we would still have true returned from this method
+        assertTrue("AbstractMarkwonPlugin", impl.hasPlugin(AbstractMarkwonPlugin.class));
+        assertTrue("MarkwonPlugin", impl.hasPlugin(MarkwonPlugin.class));
+    }
 }
\ No newline at end of file