backend/SwingComponent.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2019 Kevin Lamonte
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  *
  26  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  27  * @version 1
  28  */
  29 package jexer.backend;
  30
  31 import java.awt.Color;
  32 import java.awt.Cursor;
  33 import java.awt.Font;
  34 import java.awt.Graphics;
  35 import java.awt.Insets;
  36 import java.awt.Point;
  37 import java.awt.Toolkit;
  38 import java.awt.event.ComponentListener;
  39 import java.awt.event.KeyListener;
  40 import java.awt.event.MouseListener;
  41 import java.awt.event.MouseMotionListener;
  42 import java.awt.event.MouseWheelListener;
  43 import java.awt.event.WindowListener;
  44 import java.awt.image.BufferedImage;
  45 import java.awt.image.BufferStrategy;
  46 import java.io.IOException;
  47 import javax.imageio.ImageIO;
  48 import javax.swing.JComponent;
  49 import javax.swing.JFrame;
  50 import javax.swing.SwingUtilities;
  51
  52 /**
  53  * Wrapper for integrating with Swing, because JFrame and JComponent have
  54  * separate hierarchies.
  55  */
  56 class SwingComponent {
  57
  58     // ------------------------------------------------------------------------
  59     // Variables --------------------------------------------------------------
  60     // ------------------------------------------------------------------------
  61
  62     /**
  63      * If true, use triple buffering when drawing to a JFrame.
  64      */
  65     public static boolean tripleBuffer = true;
  66
  67     /**
  68      * The frame reference, if we are drawing to a JFrame.
  69      */
  70     private JFrame frame;
  71
  72     /**
  73      * The component reference, if we are drawing to a JComponent.
  74      */
  75     private JComponent component;
  76
  77     /**
  78      * An optional border in pixels to add.
  79      */
  80     private static final int BORDER = 1;
  81
  82     /**
  83      * Adjustable Insets for this component.  This has the effect of adding a
  84      * black border around the drawing area.
  85      */
  86     Insets adjustInsets = null;
  87
  88     // ------------------------------------------------------------------------
  89     // Constructors -----------------------------------------------------------
  90     // ------------------------------------------------------------------------
  91
  92     /**
  93      * Construct using a JFrame.
  94      *
  95      * @param frame the JFrame to draw to
  96      */
  97     public SwingComponent(final JFrame frame) {
  98         this.frame = frame;
  99         if (System.getProperty("os.name").startsWith("Linux")) {
 100             // On my Linux dev system, a Swing frame draws its contents just
 101             // a little off.  No idea why, but I've seen it on both Debian
 102             // and Fedora with KDE.  These adjustments to the adjustments
 103             // seem to center it OK in the frame.
 104             adjustInsets = new Insets(BORDER + 5, BORDER,
 105                 BORDER - 3, BORDER + 2);
 106         } else {
 107             adjustInsets = new Insets(BORDER, BORDER, BORDER, BORDER);
 108         }
 109         setupFrame();
 110     }
 111
 112     /**
 113      * Construct using a JComponent.
 114      *
 115      * @param component the JComponent to draw to
 116      */
 117     public SwingComponent(final JComponent component) {
 118         this.component = component;
 119         adjustInsets = new Insets(BORDER, BORDER, BORDER, BORDER);
 120         setupComponent();
 121     }
 122
 123     // ------------------------------------------------------------------------
 124     // SwingComponent ---------------------------------------------------------
 125     // ------------------------------------------------------------------------
 126
 127     /**
 128      * Get the BufferStrategy object needed for triple-buffering.
 129      *
 130      * @return the BufferStrategy
 131      * @throws IllegalArgumentException if this function is called when
 132      * not rendering to a JFrame
 133      */
 134     public BufferStrategy getBufferStrategy() {
 135         if (frame != null) {
 136             return frame.getBufferStrategy();
 137         } else {
 138             throw new IllegalArgumentException("BufferStrategy not used " +
 139                 "for JComponent access");
 140         }
 141     }
 142
 143     /**
 144      * Get the JFrame reference.
 145      *
 146      * @return the frame, or null if this is drawing to a JComponent
 147      */
 148     public JFrame getFrame() {
 149         return frame;
 150     }
 151
 152     /**
 153      * Get the JComponent reference.
 154      *
 155      * @return the component, or null if this is drawing to a JFrame
 156      */
 157     public JComponent getComponent() {
 158         return component;
 159     }
 160
 161     /**
 162      * Setup to render to an existing JComponent.
 163      */
 164     public void setupComponent() {
 165         component.setBackground(Color.black);
 166
 167         if (System.getProperty("jexer.Swing.mouseImage") != null) {
 168             component.setCursor(getMouseImage());
 169         } else if (System.getProperty("jexer.Swing.mouseStyle") != null) {
 170             component.setCursor(getMouseCursor());
 171         } else if (System.getProperty("jexer.textMouse",
 172                 "true").equals("false")
 173         ) {
 174             // If the user has suppressed the text mouse, don't kill the X11
 175             // mouse.
 176             component.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
 177         } else {
 178             // Kill the X11 cursor
 179             // Transparent 16 x 16 pixel cursor image.
 180             BufferedImage cursorImg = new BufferedImage(16, 16,
 181                 BufferedImage.TYPE_INT_ARGB);
 182             // Create a new blank cursor.
 183             Cursor blankCursor = Toolkit.getDefaultToolkit().createCustomCursor(
 184                 cursorImg, new Point(0, 0), "blank cursor");
 185             component.setCursor(blankCursor);
 186         }
 187
 188         // Be capable of seeing Tab / Shift-Tab
 189         component.setFocusTraversalKeysEnabled(false);
 190     }
 191
 192     /**
 193      * Setup to render to an existing JFrame.
 194      */
 195     public void setupFrame() {
 196         frame.setTitle("Jexer Application");
 197         frame.setBackground(Color.black);
 198         frame.pack();
 199
 200         if (System.getProperty("jexer.Swing.mouseImage") != null) {
 201             frame.setCursor(getMouseImage());
 202         } else if (System.getProperty("jexer.Swing.mouseStyle") != null) {
 203             frame.setCursor(getMouseCursor());
 204         } else if (System.getProperty("jexer.textMouse",
 205                 "true").equals("false")
 206         ) {
 207             // If the user has suppressed the text mouse, don't kill the X11
 208             // mouse.
 209             frame.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
 210         } else {
 211             // Kill the X11 cursor
 212             // Transparent 16 x 16 pixel cursor image.
 213             BufferedImage cursorImg = new BufferedImage(16, 16,
 214                 BufferedImage.TYPE_INT_ARGB);
 215             // Create a new blank cursor.
 216             Cursor blankCursor = Toolkit.getDefaultToolkit().createCustomCursor(
 217                 cursorImg, new Point(0, 0), "blank cursor");
 218             frame.setCursor(blankCursor);
 219         }
 220
 221         // Be capable of seeing Tab / Shift-Tab
 222         frame.setFocusTraversalKeysEnabled(false);
 223
 224         // Setup triple-buffering
 225         if (tripleBuffer) {
 226             frame.setIgnoreRepaint(true);
 227             frame.createBufferStrategy(3);
 228         }
 229     }
 230
 231     /**
 232      * Load an image named in jexer.Swing.mouseImage as the mouse cursor.
 233      * The image must be on the classpath.
 234      *
 235      * @return the cursor
 236      */
 237     private Cursor getMouseImage() {
 238         Cursor cursor = Cursor.getDefaultCursor();
 239         String filename = System.getProperty("jexer.Swing.mouseImage");
 240         assert (filename != null);
 241
 242         try {
 243             ClassLoader loader = Thread.currentThread().
 244                 getContextClassLoader();
 245
 246             java.net.URL url = loader.getResource(filename);
 247             if (url == null) {
 248                 // User named a file, but it's not on the classpath.  Bail
 249                 // out.
 250                 return cursor;
 251             }
 252
 253             BufferedImage cursorImage = ImageIO.read(url);
 254             java.awt.Dimension cursorSize = Toolkit.getDefaultToolkit().
 255                 getBestCursorSize(
 256                         cursorImage.getWidth(), cursorImage.getHeight());
 257
 258             cursor = Toolkit.getDefaultToolkit().createCustomCursor(cursorImage,
 259                 new Point((int) Math.min(cursorImage.getWidth() / 2,
 260                         cursorSize.getWidth() - 1),
 261                     (int) Math.min(cursorImage.getHeight() / 2,
 262                         cursorSize.getHeight() - 1)),
 263                 "custom cursor");
 264         } catch (IOException e) {
 265             e.printStackTrace();
 266         }
 267
 268         return cursor;
 269     }
 270
 271     /**
 272      * Get the appropriate mouse cursor based on jexer.Swing.mouseStyle.
 273      *
 274      * @return the cursor
 275      */
 276     private Cursor getMouseCursor() {
 277         Cursor cursor = Cursor.getDefaultCursor();
 278         String style = System.getProperty("jexer.Swing.mouseStyle");
 279         assert (style != null);
 280
 281         style = style.toLowerCase();
 282
 283         if (style.equals("none")) {
 284             // Transparent 16 x 16 pixel cursor image.
 285             BufferedImage cursorImg = new BufferedImage(16, 16,
 286                 BufferedImage.TYPE_INT_ARGB);
 287             // Create a new blank cursor.
 288             cursor = Toolkit.getDefaultToolkit().createCustomCursor(
 289                 cursorImg, new Point(0, 0), "blank cursor");
 290         } else if (style.equals("default")) {
 291             cursor = Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
 292         } else if (style.equals("hand")) {
 293             cursor = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
 294         } else if (style.equals("text")) {
 295             cursor = Cursor.getPredefinedCursor(Cursor.TEXT_CURSOR);
 296         } else if (style.equals("move")) {
 297             cursor = Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR);
 298         } else if (style.equals("crosshair")) {
 299             cursor = Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR);
 300         }
 301
 302         return cursor;
 303     }
 304
 305     /**
 306      * Set the window title.
 307      *
 308      * @param title the new title
 309      */
 310     public void setTitle(final String title) {
 311         if (frame != null) {
 312             frame.setTitle(title);
 313         }
 314     }
 315
 316     /**
 317      * Paints this component.
 318      *
 319      * @param g the graphics context to use for painting
 320      */
 321     public void paint(Graphics g) {
 322         if (frame != null) {
 323             frame.paint(g);
 324         } else {
 325             component.paint(g);
 326         }
 327     }
 328
 329     /**
 330      * Repaints this component.
 331      */
 332     public void repaint() {
 333         if (frame != null) {
 334             frame.repaint();
 335         } else {
 336             component.repaint();
 337         }
 338     }
 339
 340     /**
 341      * Repaints the specified rectangle of this component.
 342      *
 343      * @param x the x coordinate
 344      * @param y the y coordinate
 345      * @param width the width
 346      * @param height the height
 347      */
 348     public void repaint(int x, int y, int width, int height) {
 349         if (frame != null) {
 350             frame.repaint(x, y, width, height);
 351         } else {
 352             component.repaint(x, y, width, height);
 353         }
 354     }
 355
 356     /**
 357      * If a border has been set on this component, returns the border's
 358      * insets; otherwise calls super.getInsets.
 359      *
 360      * @return the value of the insets property
 361      */
 362     public Insets getInsets() {
 363         Insets swingInsets = null;
 364         if (frame != null) {
 365             swingInsets = frame.getInsets();
 366         } else {
 367             swingInsets = component.getInsets();
 368         }
 369         Insets result = new Insets(swingInsets.top + adjustInsets.top,
 370             swingInsets.left + adjustInsets.left,
 371             swingInsets.bottom + adjustInsets.bottom,
 372             swingInsets.right + adjustInsets.right);
 373         return result;
 374     }
 375
 376     /**
 377      * Returns the current width of this component.
 378      *
 379      * @return the current width of this component
 380      */
 381     public int getWidth() {
 382         if (frame != null) {
 383             return frame.getWidth();
 384         } else {
 385             return component.getWidth();
 386         }
 387     }
 388
 389     /**
 390      * Returns the current height of this component.
 391      *
 392      * @return the current height of this component
 393      */
 394     public int getHeight() {
 395         if (frame != null) {
 396             return frame.getHeight();
 397         } else {
 398             return component.getHeight();
 399         }
 400     }
 401
 402     /**
 403      * Gets the font of this component.
 404      *
 405      * @return this component's font; if a font has not been set for this
 406      * component, the font of its parent is returned
 407      */
 408     public Font getFont() {
 409         if (frame != null) {
 410             return frame.getFont();
 411         } else {
 412             return component.getFont();
 413         }
 414     }
 415
 416     /**
 417      * Sets the font of this component.
 418      *
 419      * @param f the font to become this component's font; if this parameter
 420      * is null then this component will inherit the font of its parent
 421      */
 422     public void setFont(final Font f) {
 423         if (frame != null) {
 424             frame.setFont(f);
 425         } else {
 426             component.setFont(f);
 427         }
 428     }
 429
 430     /**
 431      * Shows or hides this Window depending on the value of parameter b.
 432      *
 433      * @param b if true, make visible, else make invisible
 434      */
 435     public void setVisible(final boolean b) {
 436         if (frame != null) {
 437             frame.setVisible(b);
 438         } else {
 439             component.setVisible(b);
 440         }
 441     }
 442
 443     /**
 444      * Creates a graphics context for this component. This method will return
 445      * null if this component is currently not displayable.
 446      *
 447      * @return a graphics context for this component, or null if it has none
 448      */
 449     public Graphics getGraphics() {
 450         if (frame != null) {
 451             return frame.getGraphics();
 452         } else {
 453             return component.getGraphics();
 454         }
 455     }
 456
 457     /**
 458      * Releases all of the native screen resources used by this Window, its
 459      * subcomponents, and all of its owned children. That is, the resources
 460      * for these Components will be destroyed, any memory they consume will
 461      * be returned to the OS, and they will be marked as undisplayable.
 462      */
 463     public void dispose() {
 464         if (frame != null) {
 465             frame.dispose();
 466         } else {
 467             component.getParent().remove(component);
 468         }
 469     }
 470
 471     /**
 472      * Resize the component to match the font dimensions.
 473      *
 474      * @param width the new width in pixels
 475      * @param height the new height in pixels
 476      */
 477     public void setDimensions(final int width, final int height) {
 478         if (SwingUtilities.isEventDispatchThread()) {
 479             // We are in the Swing thread and can safely set the size.
 480
 481             // Figure out the thickness of borders and use that to set the
 482             // final size.
 483             if (frame != null) {
 484                 Insets insets = getInsets();
 485                 frame.setSize(width + insets.left + insets.right,
 486                     height + insets.top + insets.bottom);
 487             } else {
 488                 Insets insets = getInsets();
 489                 component.setSize(width + insets.left + insets.right,
 490                     height + insets.top + insets.bottom);
 491             }
 492             return;
 493         }
 494
 495         SwingUtilities.invokeLater(new Runnable() {
 496             public void run() {
 497                 // Figure out the thickness of borders and use that to set
 498                 // the final size.
 499                 if (frame != null) {
 500                     Insets insets = getInsets();
 501                     frame.setSize(width + insets.left + insets.right,
 502                         height + insets.top + insets.bottom);
 503                 } else {
 504                     Insets insets = getInsets();
 505                     component.setSize(width + insets.left + insets.right,
 506                         height + insets.top + insets.bottom);
 507                 }
 508             }
 509         });
 510     }
 511
 512     /**
 513      * Adds the specified component listener to receive component events from
 514      * this component. If listener l is null, no exception is thrown and no
 515      * action is performed.
 516      *
 517      * @param l the component listener
 518      */
 519     public void addComponentListener(ComponentListener l) {
 520         if (frame != null) {
 521             frame.addComponentListener(l);
 522         } else {
 523             component.addComponentListener(l);
 524         }
 525     }
 526
 527     /**
 528      * Adds the specified key listener to receive key events from this
 529      * component. If l is null, no exception is thrown and no action is
 530      * performed.
 531      *
 532      * @param l the key listener.
 533      */
 534     public void addKeyListener(KeyListener l) {
 535         if (frame != null) {
 536             frame.addKeyListener(l);
 537         } else {
 538             component.addKeyListener(l);
 539         }
 540     }
 541
 542     /**
 543      * Adds the specified mouse listener to receive mouse events from this
 544      * component. If listener l is null, no exception is thrown and no action
 545      * is performed.
 546      *
 547      * @param l the mouse listener
 548      */
 549     public void addMouseListener(MouseListener l) {
 550         if (frame != null) {
 551             frame.addMouseListener(l);
 552         } else {
 553             component.addMouseListener(l);
 554         }
 555     }
 556
 557     /**
 558      * Adds the specified mouse motion listener to receive mouse motion
 559      * events from this component. If listener l is null, no exception is
 560      * thrown and no action is performed.
 561      *
 562      * @param l the mouse motion listener
 563      */
 564     public void addMouseMotionListener(MouseMotionListener l) {
 565         if (frame != null) {
 566             frame.addMouseMotionListener(l);
 567         } else {
 568             component.addMouseMotionListener(l);
 569         }
 570     }
 571
 572     /**
 573      * Adds the specified mouse wheel listener to receive mouse wheel events
 574      * from this component. Containers also receive mouse wheel events from
 575      * sub-components.
 576      *
 577      * @param l the mouse wheel listener
 578      */
 579     public void addMouseWheelListener(MouseWheelListener l) {
 580         if (frame != null) {
 581             frame.addMouseWheelListener(l);
 582         } else {
 583             component.addMouseWheelListener(l);
 584         }
 585     }
 586
 587     /**
 588      * Adds the specified window listener to receive window events from this
 589      * window. If l is null, no exception is thrown and no action is
 590      * performed.
 591      *
 592      * @param l the window listener
 593      */
 594     public void addWindowListener(WindowListener l) {
 595         if (frame != null) {
 596             frame.addWindowListener(l);
 597         }
 598     }
 599
 600     /**
 601      * Requests that this Component get the input focus, if this Component's
 602      * top-level ancestor is already the focused Window.
 603      */
 604     public void requestFocusInWindow() {
 605         if (frame != null) {
 606             frame.requestFocusInWindow();
 607         } else {
 608             component.requestFocusInWindow();
 609         }
 610     }
 611
 612 }