Added SelectionMode enum to ComponentList, prepared integration

These changes are not ready to build yet, as ChatWindow and
ContactsChooserDialog have to be adjusted first.

src/main/java/envoy/client/ui/container/ChatWindow.java

@@ -131,12 +131,12 @@ public class ChatWindow extends JFrame {
 
 			{
 				put("forward selected message",
-						evt -> forwardMessageToMultipleUsers(messageList.getSelected().get(0),
-								ContactsChooserDialog.showForwardingDialog("Forward selected message to", messageList.getSelected().get(0), client)));
+						evt -> forwardMessageToMultipleUsers(messageList.getSelection().get(0),
+								ContactsChooserDialog.showForwardingDialog("Forward selected message to", messageList.getSelection().get(0), client)));
 				put("copy", evt -> {
 					// TODO should be enhanced to allow also copying of message attachments,
 					// especially pictures
-					StringSelection copy = new StringSelection(messageList.getSelected().get(0).getText());
+					StringSelection copy = new StringSelection(messageList.getSelection().get(0).getText());
 					Toolkit.getDefaultToolkit().getSystemClipboard().setContents(copy, copy);
 				});
 				// TODO insert implementation to edit and delete messages

src/main/java/envoy/client/ui/container/ContactsChooserDialog.java

@@ -69,7 +69,7 @@ public class ContactsChooserDialog extends JDialog {
 		dialog.getContentPanel()
 			.add(new MessageListRenderer(client.getSender().getId()).getListCellComponent(null, message, false), BorderLayout.NORTH);
 		List<User> results = new ArrayList<>();
-		dialog.addOkButtonActionListener(e -> { results.addAll(dialog.getContactList().getSelected()); dialog.dispose(); });
+		dialog.addOkButtonActionListener(e -> { results.addAll(dialog.getContactList().getSelection()); dialog.dispose(); });
 		ComponentListModel<User> contactListModel = dialog.getContactList().getModel();
 		client.getContacts().getContacts().forEach(user -> contactListModel.add(user));
 		dialog.setVisible(true);

src/main/java/envoy/client/ui/list/ComponentList.java

@@ -3,8 +3,8 @@ package envoy.client.ui.list;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseListener;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 
 import javax.swing.*;
 
@@ -25,15 +25,17 @@ public class ComponentList<E> extends JPanel {
 
 	private ComponentListModel<E>			model;
 	private ComponentListCellRenderer<E>	renderer;
-	private boolean							multipleSelectionEnabled	= false;
-
-	private List<Integer> currentSelections = new ArrayList<>();
+	private SelectionMode					selectionMode	= SelectionMode.NONE;
+	private Set<Integer>					selection		= new HashSet<>();
 
 	private static final long serialVersionUID = 1759644503942876737L;
 
+	public static enum SelectionMode {
+		NONE, SINGLE, MULTIPLE
+	}
+
 	/**
-	 * Sets the layout of this {@link ComponentList} to be a vertically oriented
-	 * BoxLayout.
+	 * Initializes a default {@link ComponentList} without a model or a renderer.
 	 *
 	 * @since Envoy v0.1-beta
 	 */
@@ -79,8 +81,8 @@ public class ComponentList<E> extends JPanel {
 
 		// Synchronize with new model
 		this.model = model;
-		if (model != null) this.model.setComponentList(this);
-		if (renderer != null) synchronizeModel();
+		if (model != null) model.setComponentList(this);
+		synchronizeModel();
 	}
 
 	/**
@@ -92,11 +94,53 @@ public class ComponentList<E> extends JPanel {
 	public void synchronizeModel() {
 		if (model != null && renderer != null) {
 			removeAll();
-			model.forEach(this::add);
+			model.forEach(this::addElement);
 			revalidate();
 		}
 	}
 
+	/**
+	 * Selects a list element by index. If the element is already selected, it is
+	 * removed from the selection.
+	 *
+	 * @param index the index of the selected component
+	 * @since Envoy v0.1-beta
+	 */
+	public void selectElement(int index) {
+		if (selection.contains(index)) {
+
+			// Remove selection of element at index
+			updateElement(index, false);
+			selection.remove(index);
+		} else {
+
+			// Remove old selection if single selection is enabled
+			if (selectionMode == SelectionMode.SINGLE) clearSelection();
+
+			if (selectionMode != SelectionMode.NONE) {
+
+				// Assign new selection
+				selection.add(index);
+
+				// Update element
+				updateElement(index, true);
+			}
+		}
+
+		revalidate();
+		repaint();
+	}
+
+	/**
+	 * Removes the current selection.
+	 * 
+	 * @since Envoy v0.1-alpha
+	 */
+	public void clearSelection() {
+		selection.forEach(i -> updateElement(i, false));
+		selection.clear();
+	}
+
 	/**
 	 * Adds an object to the list by rendering it with the current
 	 * {@link ComponentListCellRenderer}.
@@ -104,89 +148,26 @@ public class ComponentList<E> extends JPanel {
 	 * @param elem the element to add
 	 * @since Envoy v0.3-alpha
 	 */
-	void add(E elem) { add(elem, getComponentCount(), false); }
+	void addElement(E elem) { addElement(elem, getComponentCount(), false); }
 
 	/**
 	 * Adds an object to the list by rendering it with the current
-	 * {@link ComponentListRenderer}.
+	 * {@link ComponentListRenderer}. If the renderer is {@code null}, no action is
+	 * performed.
 	 *
 	 * @param elem       the element to add
 	 * @param index      the index at which to add the element
 	 * @param isSelected the selection state of the element
 	 * @since Envoy v0.1-beta
 	 */
-	private void add(E elem, int index, boolean isSelected) {
-		if (isSelected && !multipleSelectionEnabled) {
-			clearSelections();
-			currentSelections.add(index);
-		}
+	private void addElement(E elem, int index, boolean isSelected) {
 		if (renderer != null) {
-		final JComponent component = renderer.getListCellComponent(this, elem, isSelected);
-		component.addMouseListener(getSelectionListener(index));
-		add(component, index);
+			final JComponent component = renderer.getListCellComponent(this, elem, isSelected);
+			component.addMouseListener(getSelectionListener(index));
+			add(component, index);
 		}
 	}
 
-	/**
-	 * @param componentIndex the index of the list component to which the mouse
-	 *                       listener will be added
-	 * @return a mouse listener calling the
-	 *         {@link ComponentList#componentSelected(int)} method with the
-	 *         component's index when a left click is performed by the user
-	 * @since Envoy v0.1-beta
-	 */
-	private MouseListener getSelectionListener(int componentIndex) {
-		return new MouseAdapter() {
-
-			@Override
-			public void mouseClicked(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e)) componentSelected(componentIndex); }
-		};
-	}
-
-	/**
-	 * Gets called when a list component has been clicked on by the user. Any
-	 * previous selections are then removed and the selected component gets
-	 * redrawn.<br>
-	 * <br>
-	 * If the currently selected component gets selected again, the selection is
-	 * removed.
-	 *
-	 * @param index the index of the selected component
-	 * @since Envoy v0.1-beta
-	 */
-	private void componentSelected(int index) {
-		// removing selection of element at index
-		if (currentSelections.contains(index)) {
-
-			// Clear selection
-			updateSelection(index, false);
-			currentSelections.remove(Integer.valueOf(index));
-		} else {
-
-			// Remove old selection if multipleSelection is disabled
-			if (!multipleSelectionEnabled && currentSelections.size() > 0) clearSelections();
-
-			// Assign new selection
-			currentSelections.add(index);
-
-			// Update current selection
-			updateSelection(index, true);
-		}
-
-		revalidate();
-		repaint();
-	}
-
-	/**
-	 * Clears all currently active selections.
-	 *
-	 * @since Envoy v0.1-beta
-	 */
-	private void clearSelections() {
-		currentSelections.forEach(index -> updateSelection(index, false));
-		currentSelections.clear();
-	}
-
 	/**
 	 * Replaces a list element with a newly rendered instance of its contents.
 	 *
@@ -194,21 +175,33 @@ public class ComponentList<E> extends JPanel {
 	 * @param isSelected the selection state passed to the {@link ListCellRenderer}
 	 * @since Envoy v0.1-beta
 	 */
-	private void updateSelection(int index, boolean isSelected) {
+	private void updateElement(int index, boolean isSelected) {
 		remove(index);
-		add(model.get(index), index, isSelected);
+		addElement(model.get(index), index, isSelected);
 	}
 
 	/**
-	 * @return the selected elements or null if none is selected
+	 * @param componentIndex the index of the list component to which the mouse
+	 *                       listener will be added
+	 * @return a mouse listener calling the
+	 *         {@link ComponentList#selectElement(int)} method with the
+	 *         component's index when a left click is performed by the user
 	 * @since Envoy v0.1-beta
 	 */
-	public List<E> getSelected() {
-		List<E> selected = new ArrayList<>();
-		currentSelections.forEach(index -> selected.add(model.get(index)));
-		return selected;
+	private MouseListener getSelectionListener(int componentIndex) {
+		return new MouseAdapter() {
+
+			@Override
+			public void mouseClicked(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e)) selectElement(componentIndex); }
+		};
 	}
 
+	/**
+	 * @return a set of all selected indices
+	 * @since Envoy v0.1-beta
+	 */
+	public Set<Integer> getSelection() { return selection; }
+
 	/**
 	 * @return the model
 	 * @since Envoy v0.1-beta
@@ -228,37 +221,14 @@ public class ComponentList<E> extends JPanel {
 	public void setRenderer(ComponentListCellRenderer<E> renderer) { this.renderer = renderer; }
 
 	/**
-	 * @return the multipleSelectionEnabled
+	 * @return the selectionMode
 	 * @since Envoy v0.1-beta
 	 */
-	public boolean isMultipleSelectionEnabled() { return multipleSelectionEnabled; }
+	public SelectionMode getSelectionMode() { return selectionMode; }
 
 	/**
-	 * @param multipleSelectionEnabled if true, multiple elements can be selected in
-	 *                                 the component list
+	 * @param selectionMode the selectionMode to set
 	 * @since Envoy v0.1-beta
 	 */
-	public void setMultipleSelectionEnabled(boolean multipleSelectionEnabled) {
-		this.multipleSelectionEnabled = multipleSelectionEnabled;
-		if (!multipleSelectionEnabled) clearSelections();
-	}
-
-	/**
-	 * Enables the selection of multiple elements.
-	 *
-	 * @see ComponentList#disableMultipleSelection
-	 * @since Envoy v0.1-beta
-	 */
-	public void enableMultipleSelection() { this.multipleSelectionEnabled = true; }
-
-	/**
-	 * Allows only one element to be selected. True by default.
-	 *
-	 * @see ComponentList#enableMultipleSelection
-	 * @since Envoy v0.1-beta
-	 */
-	public void disableMultipleSelection() {
-		this.multipleSelectionEnabled = false;
-		clearSelections();
-	}
+	public void setSelectionMode(SelectionMode selectionMode) { this.selectionMode = selectionMode; }
 }

src/main/java/envoy/client/ui/list/ComponentListModel.java

@@ -34,7 +34,7 @@ public final class ComponentListModel<E> implements Iterable<E>, Serializable {
 	 */
 	public boolean add(E e) {
 		if (componentList != null) {
-			componentList.add(e);
+			componentList.addElement(e);
 			componentList.revalidate();
 		}
 		return elements.add(e);