1 files changed, 101 insertions, 0 deletions
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/templates/StringEvaluator.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/templates/StringEvaluator.java
new file mode 100644
index 000000000..c1c8073c0
--- /dev/null
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/wizards/templates/StringEvaluator.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Eclipse Public License, Version 1.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.eclipse.org/org/documents/epl-v10.php
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.ide.eclipse.adt.internal.wizards.templates;
+
+import static com.android.tools.lint.detector.api.LintUtils.assertionsEnabled;
+
+import com.android.annotations.NonNull;
+import com.android.annotations.Nullable;
+import com.android.ide.eclipse.adt.AdtPlugin;
+
+import freemarker.cache.TemplateLoader;
+import freemarker.template.Configuration;
+import freemarker.template.DefaultObjectWrapper;
+import freemarker.template.Template;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A template handler which can evaluate simple strings. Used to evaluate
+ * parameter constraints during UI wizard value editing.
+ * <p>
+ * Unlike the more general {@link TemplateHandler} which is used to instantiate
+ * full template files (from resources, merging into existing files etc) this
+ * evaluator supports only simple strings, referencing only values from the
+ * provided map (and builtin functions).
+ */
+class StringEvaluator implements TemplateLoader {
+    private Map<String, Object> mParameters;
+    private Configuration mFreemarker;
+    private String mCurrentExpression;
+
+    StringEvaluator() {
+        mParameters = TemplateHandler.createBuiltinMap();
+
+        mFreemarker = new Configuration();
+        mFreemarker.setObjectWrapper(new DefaultObjectWrapper());
+        mFreemarker.setTemplateLoader(this);
+    }
+
+    /** Evaluates the given expression, with the given set of parameters */
+    @Nullable
+    String evaluate(@NonNull String expression, @NonNull List<Parameter> parameters) {
+        // Render the instruction list template.
+        for (Parameter parameter : parameters) {
+            mParameters.put(parameter.id, parameter.value);
+        }
+        try {
+            mCurrentExpression = expression;
+            Template inputsTemplate = mFreemarker.getTemplate(expression);
+            StringWriter out = new StringWriter();
+            inputsTemplate.process(mParameters, out);
+            out.flush();
+            return out.toString();
+        } catch (Exception e) {
+            if (assertionsEnabled()) {
+                AdtPlugin.log(e, null);
+            }
+            return null;
+        }
+    }
+
+    // ---- Implements TemplateLoader ----
+
+    @Override
+    public Object findTemplateSource(String name) throws IOException {
+        return mCurrentExpression;
+    }
+
+    @Override
+    public long getLastModified(Object templateSource) {
+        return 0;
+    }
+
+    @Override
+    public Reader getReader(Object templateSource, String encoding) throws IOException {
+        return new StringReader(mCurrentExpression);
+    }
+
+    @Override
+    public void closeTemplateSource(Object templateSource) throws IOException {
+    }
+}