Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.utils.datastructures / src / org / simantics / utils / datastructures / hints / IHintStack.java

diff --git a/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/hints/IHintStack.java b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/hints/IHintStack.java
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+++ b/bundles/org.simantics.utils.datastructures/src/org/simantics/utils/datastructures/hints/IHintStack.java
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+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+/*\r
+ *\r
+ * @author Toni Kalajainen\r
+ */\r
+package org.simantics.utils.datastructures.hints;\r
+\r
+\r
+/**\r
+ * IHintStack is a layered stack of hint contexts.  \r
+ * Each hint context has a priority. \r
+ * Hint set in higher priority context overrides all lower priority hints of \r
+ * the same key.\r
+ * \r
+ * Hint set in a hint context does not become effective if there \r
+ * exists another hint of the same key in a higher priority context. \r
+ * \r
+ * If the higher priority context or its hint is removed, the next lower level hint\r
+ * becomes effective.\r
+ * \r
+ * getHint() method is global. It returns the highest priority value for the key.\r
+ * It does not return the hint set for a specific context, instead it returns the hint\r
+ * set in the highest priority context.  \r
+ */\r
+public interface IHintStack extends IHintObservable {\r
+\r
+       void addHintContext(IHintContext hints, int priority);\r
+       \r
+       boolean removeHintContext(IHintContext hints);\r
+       \r
+       /**\r
+        * Returns a wrapper hint context whose read operations originate from the stack, and\r
+        * write operations to the a local stack (argument ctx)\r
+        * \r
+     * @param ctx the hint context to write into\r
+     * @return write-localized hint context based on this hint stack\r
+        */\r
+       IHintContext createStackRead(final IHintContext ctx);   \r
+       \r
+}\r