sample, change bullet span

app-sample/samples.json

@@ -1,4 +1,18 @@
 [
+  {
+    "javaClassName": "io.noties.markwon.app.samples.ChangeBulletSpanSample",
+    "id": "20201208150530",
+    "title": "Change bullet span",
+    "description": "Use a different span implementation to render bullet lists",
+    "artifacts": [
+      "CORE"
+    ],
+    "tags": [
+      "rendering",
+      "span",
+      "span-factory"
+    ]
+  },
   {
     "javaClassName": "io.noties.markwon.app.samples.HeadingColorSample",
     "id": "20201203224611",

app-sample/src/main/java/io/noties/markwon/app/sample/Tags.kt

@@ -34,4 +34,5 @@ object Tags {
     const val knownBug = "known-bug"
     const val precomputedText = "precomputed-text"
     const val cache = "cache"
+    const val spanFactory = "span-factory"
 }

app-sample/src/main/java/io/noties/markwon/app/samples/ChangeBulletSpanSample.java

@@ -0,0 +1,66 @@
+package io.noties.markwon.app.samples;
+
+import android.text.style.BulletSpan;
+
+import androidx.annotation.NonNull;
+
+import org.commonmark.node.ListItem;
+
+import io.noties.debug.Debug;
+import io.noties.markwon.AbstractMarkwonPlugin;
+import io.noties.markwon.Markwon;
+import io.noties.markwon.MarkwonSpansFactory;
+import io.noties.markwon.SpanFactory;
+import io.noties.markwon.app.sample.Tags;
+import io.noties.markwon.app.sample.ui.MarkwonTextViewSample;
+import io.noties.markwon.core.CoreProps;
+import io.noties.markwon.ext.tasklist.TaskListPlugin;
+import io.noties.markwon.sample.annotations.MarkwonArtifact;
+import io.noties.markwon.sample.annotations.MarkwonSampleInfo;
+
+@MarkwonSampleInfo(
+  id = "20201208150530",
+  title = "Change bullet span",
+  description = "Use a different span implementation to render bullet lists",
+  artifacts = MarkwonArtifact.CORE,
+  tags = {Tags.rendering, Tags.spanFactory, Tags.span}
+)
+public class ChangeBulletSpanSample extends MarkwonTextViewSample {
+  @Override
+  public void render() {
+    final String md = "" +
+      "* one\n" +
+      "* two\n" +
+      "* three\n" +
+      "* * four\n" +
+      "  * five\n\n" +
+      "- [ ] and task?\n" +
+      "- [x] it is";
+
+    final Markwon markwon = Markwon.builder(context)
+      .usePlugin(TaskListPlugin.create(context))
+      .usePlugin(new AbstractMarkwonPlugin() {
+        @Override
+        public void configureSpansFactory(@NonNull MarkwonSpansFactory.Builder builder) {
+
+          // store original span factory (provides both bullet and ordered lists)
+          final SpanFactory original = builder.getFactory(ListItem.class);
+
+          builder.setFactory(ListItem.class, (configuration, props) -> {
+            if (CoreProps.LIST_ITEM_TYPE.require(props) == CoreProps.ListItemType.BULLET) {
+              // additionally inspect bullet level
+              final int level = CoreProps.BULLET_LIST_ITEM_LEVEL.require(props);
+              Debug.i("rendering bullet list with level: %d", level);
+
+              // return _system_ bullet span, but can be any
+              return new BulletSpan();
+            }
+            return original != null ? original.getSpans(configuration, props) : null;
+          });
+        }
+      })
+      .build();
+
+    markwon.setMarkdown(textView, md);
+  }
+}