Code refactoring.

[sixth-3d.git] / src / main / java / eu / svjatoslav / sixth / e3d / gui / humaninput / KeyboardFocusStack.java

diff --git a/src/main/java/eu/svjatoslav/sixth/e3d/gui/humaninput/KeyboardFocusStack.java b/src/main/java/eu/svjatoslav/sixth/e3d/gui/humaninput/KeyboardFocusStack.java
new file mode 100644 (file)
index 0000000..4ee7ed8
--- /dev/null
+++ b/src/main/java/eu/svjatoslav/sixth/e3d/gui/humaninput/KeyboardFocusStack.java
@@ -0,0 +1,55 @@
+/*
+ * Sixth 3D engine. Copyright ©2012-2018, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 3 of the GNU Lesser General Public License
+ * or later as published by the Free Software Foundation.
+ *
+ */
+
+package eu.svjatoslav.sixth.e3d.gui.humaninput;
+
+import eu.svjatoslav.sixth.e3d.gui.ViewPanel;
+
+import java.util.Stack;
+
+public class KeyboardFocusStack {
+
+    private final ViewPanel viewPanel;
+    private WorldNavigationUserInputTracker defaultInputHandler = new WorldNavigationUserInputTracker();
+    private Stack<UserInputHandler> inputHandlers = new Stack<>();
+    private UserInputHandler currentUserInputHandler;
+
+    public KeyboardFocusStack(final ViewPanel viewPanel) {
+        this.viewPanel = viewPanel;
+        pushFocusOwner(defaultInputHandler);
+    }
+
+    public UserInputHandler getCurrentFocusOwner() {
+        return currentUserInputHandler;
+    }
+
+    public void popFocusOwner() {
+        if (currentUserInputHandler != null)
+            currentUserInputHandler.focusLost(viewPanel);
+
+        if (inputHandlers.isEmpty())
+            return;
+
+        currentUserInputHandler = inputHandlers.pop();
+        currentUserInputHandler.focusReceived(viewPanel);
+    }
+
+    public void pushFocusOwner(final UserInputHandler newInputHandler) {
+        if (currentUserInputHandler == newInputHandler)
+            return;
+
+        if (currentUserInputHandler != null) {
+            currentUserInputHandler.focusLost(viewPanel);
+            inputHandlers.push(currentUserInputHandler);
+        }
+
+        currentUserInputHandler = newInputHandler;
+        currentUserInputHandler.focusReceived(viewPanel);
+    }
+}