[live templates] Add custom macro

live_templates/src/main/java/org/intellij/sdk/liveTemplates/TitleCaseMacro.java

@@ -0,0 +1,41 @@
+// Copyright 2000-2020 JetBrains s.r.o. and other contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+
+package org.intellij.sdk.liveTemplates;
+
+import com.intellij.codeInsight.template.*;
+import com.intellij.codeInsight.template.macro.MacroBase;
+import com.intellij.openapi.util.text.StringUtil;
+import org.jetbrains.annotations.NotNull;
+
+public class TitleCaseMacro extends MacroBase {
+
+  public TitleCaseMacro() {
+    super("TitleCase", "TitleCase(String)");
+  }
+
+  /**
+   * Strictly to uphold contract for constructors in base class.
+   */
+  private TitleCaseMacro(String name, String description) {
+    super(name, description);
+  }
+
+  @Override
+  protected Result calculateResult(@NotNull Expression[] params, ExpressionContext context, boolean quick) {
+    String text = getTextResult(params, context, true);
+    if (text != null) {
+      if (text.length() > 0) {
+        text = StringUtil.toTitleCase(text);
+      }
+      return new TextResult(text);
+    }
+    return null;
+  }
+
+  @Override
+  public boolean isAcceptableInContext(TemplateContextType context) {
+    // Might want to be less restrictive in future
+    return (context instanceof MarkdownContext);
+  }
+
+}

live_templates/src/main/resources/META-INF/plugin.xml

@@ -34,8 +34,12 @@
   <vendor url="https://plugins.jetbrains.com">IntelliJ Platform SDK</vendor>
 
   <extensions defaultExtensionNs="com.intellij">
+    <!-- Declare where the IntelliJ Platform should look to find XML-based Live Templates   -->
     <defaultLiveTemplates file="/liveTemplates/Markdown"/>
+    <!-- Declare the implementation for determining the context for applying Live Templates   -->
     <liveTemplateContext implementation="org.intellij.sdk.liveTemplates.MarkdownContext"/>
+    <!-- Declare implementation-based Live Template -->
+    <liveTemplateMacro implementation="org.intellij.sdk.liveTemplates.TitleCaseMacro"/>
   </extensions>
 
 </idea-plugin>

live_templates/src/main/resources/liveTemplates/Markdown.xml

@@ -10,4 +10,15 @@
       <option name="MARKDOWN" value="true"/>
     </context>
   </template>
+  <template name="tc"
+            value="$TITLE$"
+            shortcut="NONE"
+            description="SDK: Convert to title case"
+            toReformat="true"
+            toShortenFQNames="false">
+    <variable name="TITLE" expression="TitleCase(String)" defaultValue="" alwaysStopAt="true" />
+    <context>
+      <option name="MARKDOWN" value="true" />
+    </context>
+  </template>
 </templateSet>