+/*
+ * Jexer - Java Text User Interface
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (C) 2019 Kevin Lamonte
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * @author Kevin Lamonte [kevin.lamonte@gmail.com]
+ * @version 1
+ */
+package jexer.ttree;
+
+import jexer.TAction;
+import jexer.TKeypress;
+import jexer.TWidget;
+import jexer.event.TKeypressEvent;
+import static jexer.TKeypress.*;
+
+/**
+ * TTreeView implements a simple tree view.
+ */
+public class TTreeView extends TWidget {
+
+ // ------------------------------------------------------------------------
+ // Variables --------------------------------------------------------------
+ // ------------------------------------------------------------------------
+
+ /**
+ * Root of the tree.
+ */
+ private TTreeItem treeRoot;
+
+ /**
+ * Only one of my children can be selected.
+ */
+ private TTreeItem selectedItem = null;
+
+ /**
+ * The action to perform when the user selects an item.
+ */
+ private TAction action = null;
+
+ /**
+ * The top line currently visible.
+ */
+ private int topLine = 0;
+
+ /**
+ * The left column currently visible.
+ */
+ private int leftColumn = 0;
+
+ // ------------------------------------------------------------------------
+ // Constructors -----------------------------------------------------------
+ // ------------------------------------------------------------------------
+
+ /**
+ * Public constructor.
+ *
+ * @param parent parent widget
+ * @param x column relative to parent
+ * @param y row relative to parent
+ * @param width width of tree view
+ * @param height height of tree view
+ */
+ public TTreeView(final TWidget parent, final int x, final int y,
+ final int width, final int height) {
+
+ this(parent, x, y, width, height, null);
+ }
+
+ /**
+ * Public constructor.
+ *
+ * @param parent parent widget
+ * @param x column relative to parent
+ * @param y row relative to parent
+ * @param width width of tree view
+ * @param height height of tree view
+ * @param action action to perform when an item is selected
+ */
+ public TTreeView(final TWidget parent, final int x, final int y,
+ final int width, final int height, final TAction action) {
+
+ super(parent, x, y, width, height);
+ this.action = action;
+ }
+
+ // ------------------------------------------------------------------------
+ // Event handlers ---------------------------------------------------------
+ // ------------------------------------------------------------------------
+
+ /**
+ * Handle keystrokes.
+ *
+ * @param keypress keystroke event
+ */
+ @Override
+ public void onKeypress(final TKeypressEvent keypress) {
+ if (keypress.equals(kbUp)) {
+ // Select the previous item
+ if (selectedItem != null) {
+ if (selectedItem.keyboardPrevious != null) {
+ setSelected(selectedItem.keyboardPrevious, true);
+ }
+ }
+ } else if (keypress.equals(kbDown)) {
+ // Select the next item
+ if (selectedItem != null) {
+ if (selectedItem.keyboardNext != null) {
+ setSelected(selectedItem.keyboardNext, true);
+ }
+ }
+ } else if (keypress.equals(kbPgDn)) {
+ for (int i = 0; i < getHeight() - 1; i++) {
+ onKeypress(new TKeypressEvent(TKeypress.kbDown));
+ }
+ } else if (keypress.equals(kbPgUp)) {
+ for (int i = 0; i < getHeight() - 1; i++) {
+ onKeypress(new TKeypressEvent(TKeypress.kbUp));
+ }
+ } else if (keypress.equals(kbHome)) {
+ setSelected((TTreeItem) getChildren().get(0), false);
+ setTopLine(0);
+ } else if (keypress.equals(kbEnd)) {
+ setSelected((TTreeItem) getChildren().get(getChildren().size() - 1),
+ true);
+ } else {
+ if (selectedItem != null) {
+ selectedItem.onKeypress(keypress);
+ } else {
+ // Pass other keys (tab etc.) on to TWidget's handler.
+ super.onKeypress(keypress);
+ }
+ }
+ }
+
+ // ------------------------------------------------------------------------
+ // TWidget ----------------------------------------------------------------
+ // ------------------------------------------------------------------------
+
+
+ // ------------------------------------------------------------------------
+ // TTreeView --------------------------------------------------------------
+ // ------------------------------------------------------------------------
+
+ /**
+ * Get the root of the tree.
+ *
+ * @return the root of the tree
+ */
+ public final TTreeItem getTreeRoot() {
+ return treeRoot;
+ }
+
+ /**
+ * Set the root of the tree.
+ *
+ * @param treeRoot the new root of the tree
+ */
+ public final void setTreeRoot(final TTreeItem treeRoot) {
+ this.treeRoot = treeRoot;
+ alignTree();
+ }
+
+ /**
+ * Get the tree view item that was selected.
+ *
+ * @return the selected item, or null if no item is selected
+ */
+ public final TTreeItem getSelected() {
+ return selectedItem;
+ }
+
+ /**
+ * Set the new selected tree view item.
+ *
+ * @param item new item that became selected
+ * @param centerWindow if true, move the window to put the selected into
+ * view
+ */
+ public void setSelected(final TTreeItem item, final boolean centerWindow) {
+ if (item != null) {
+ item.setSelected(true);
+ }
+ if ((selectedItem != null) && (selectedItem != item)) {
+ selectedItem.setSelected(false);
+ }
+ selectedItem = item;
+
+ if (centerWindow) {
+ int y = 0;
+ for (TWidget widget: getChildren()) {
+ if (widget == selectedItem) {
+ break;
+ }
+ y++;
+ }
+ topLine = y - (getHeight() - 1)/2;
+ if (topLine > getChildren().size() - getHeight()) {
+ topLine = getChildren().size() - getHeight();
+ }
+ if (topLine < 0) {
+ topLine = 0;
+ }
+ }
+
+ if (selectedItem != null) {
+ activate(selectedItem);
+ }
+ }
+
+ /**
+ * Perform user selection action.
+ */
+ public void dispatch() {
+ if (action != null) {
+ action.DO(this);
+ }
+ }
+
+ /**
+ * Get the left column value. 0 is the leftmost column.
+ *
+ * @return the left column
+ */
+ public int getLeftColumn() {
+ return leftColumn;
+ }
+
+ /**
+ * Set the left column value. 0 is the leftmost column.
+ *
+ * @param leftColumn the new left column
+ */
+ public void setLeftColumn(final int leftColumn) {
+ this.leftColumn = leftColumn;
+ }
+
+ /**
+ * Get the top line (row) value. 0 is the topmost line.
+ *
+ * @return the top line
+ */
+ public int getTopLine() {
+ return topLine;
+ }
+
+ /**
+ * Set the top line value. 0 is the topmost line.
+ *
+ * @param topLine the new top line
+ */
+ public void setTopLine(final int topLine) {
+ this.topLine = topLine;
+ }
+
+ /**
+ * Get the total line (rows) count, based on the items that are visible
+ * and expanded.
+ *
+ * @return the line count
+ */
+ public int getTotalLineCount() {
+ if (treeRoot == null) {
+ return 0;
+ }
+ return getChildren().size();
+ }
+
+ /**
+ * Get the length of the widest item to display.
+ *
+ * @return the maximum number of columns for this item or its children
+ */
+ public int getMaximumColumn() {
+ if (treeRoot == null) {
+ return 0;
+ }
+ return treeRoot.getMaximumColumn();
+ }
+
+ /**
+ * Update the Y positions of all the children items to match the current
+ * topLine value. Note package private access.
+ */
+ void alignTree() {
+ if (treeRoot == null) {
+ return;
+ }
+
+ // As we walk the list we also adjust next/previous pointers,
+ // resulting in a doubly-linked list but only of the expanded items.
+ TTreeItem p = null;
+
+ for (int i = 0; i < getChildren().size(); i++) {
+ TTreeItem item = (TTreeItem) getChildren().get(i);
+
+ if (p != null) {
+ item.keyboardPrevious = p;
+ p.keyboardNext = item;
+ }
+ p = item;
+
+ item.setY(i - topLine);
+ item.setWidth(getWidth());
+ }
+
+ }
+
+}