/*

 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package javax.swing.plaf.basic;

import java.util.*;

import java.awt.*;

import java.awt.event.*;

import java.awt.datatransfer.*;

import java.awt.geom.Point2D;

import java.awt.geom.Rectangle2D;

import java.awt.im.InputContext;

import java.beans.*;

import java.io.*;

import javax.swing.*;

import javax.swing.plaf.*;

import javax.swing.text.*;

import javax.swing.event.*;

import javax.swing.border.Border;

import javax.swing.plaf.UIResource;

import javax.swing.plaf.synth.SynthUI;

import sun.swing.DefaultLookup;

import sun.awt.AppContext;

import sun.swing.SwingUtilities2;

import javax.swing.plaf.basic.DragRecognitionSupport.BeforeDrag;

/**

 * <p>

 * Basis of a text components look-and-feel.  This provides the

 * basic editor view and controller services that may be useful

 * when creating a look-and-feel for an extension of

 * <code>JTextComponent</code>.

 * <p>

 * Most state is held in the associated <code>JTextComponent</code>

 * as bound properties, and the UI installs default values for the

 * various properties.  This default will install something for

 * all of the properties.  Typically, a LAF implementation will

 * do more however.  At a minimum, a LAF would generally install

 * key bindings.

 * <p>

 * This class also provides some concurrency support if the

 * <code>Document</code> associated with the JTextComponent is a subclass of

 * <code>AbstractDocument</code>.  Access to the View (or View hierarchy) is

 * serialized between any thread mutating the model and the Swing

 * event thread (which is expected to render, do model/view coordinate

 * translation, etc).  <em>Any access to the root view should first

 * acquire a read-lock on the AbstractDocument and release that lock

 * in a finally block.</em>

 * <p>

 * An important method to define is the {@link #getPropertyPrefix} method

 * which is used as the basis of the keys used to fetch defaults

 * from the UIManager.  The string should reflect the type of

 * TextUI (eg. TextField, TextArea, etc) without the particular

 * LAF part of the name (eg Metal, Motif, etc).

 * <p>

 * To build a view of the model, one of the following strategies

 * can be employed.

 * <ol>

 * <li>

 * One strategy is to simply redefine the

 * ViewFactory interface in the UI.  By default, this UI itself acts

 * as the factory for View implementations.  This is useful

 * for simple factories.  To do this reimplement the

 * {@link #create} method.

 * <li>

 * A common strategy for creating more complex types of documents

 * is to have the EditorKit implementation return a factory.  Since

 * the EditorKit ties all of the pieces necessary to maintain a type

 * of document, the factory is typically an important part of that

 * and should be produced by the EditorKit implementation.

 * </ol>

 * <p>

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans™

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @author Timothy Prinzing

 * @author Shannon Hickey (drag and drop)

 */

@SuppressWarnings("serial") // Same-version serialization only

public abstract class BasicTextUI extends TextUI implements ViewFactory {

    private static final int DEFAULT_CARET_MARGIN = 1;

    /**

     * Creates a new UI.

     */

    public BasicTextUI() {

        painted = false;

    }

    /**

     * Creates the object to use for a caret.  By default an

     * instance of BasicCaret is created.  This method

     * can be redefined to provide something else that implements

     * the InputPosition interface or a subclass of JCaret.

     *

     * @return the caret object

     */

    protected Caret createCaret() {

        return new BasicCaret();

    }

    /**

     * Creates the object to use for adding highlights.  By default

     * an instance of BasicHighlighter is created.  This method

     * can be redefined to provide something else that implements

     * the Highlighter interface or a subclass of DefaultHighlighter.

     *

     * @return the highlighter

     */

    protected Highlighter createHighlighter() {

        return new BasicHighlighter();

    }

    /**

     * Fetches the name of the keymap that will be installed/used

     * by default for this UI. This is implemented to create a

     * name based upon the classname.  The name is the name

     * of the class with the package prefix removed.

     *

     * @return the name

     */

    protected String getKeymapName() {

        String nm = getClass().getName();

        int index = nm.lastIndexOf('.');

        if (index >= 0) {

            nm = nm.substring(index+1, nm.length());

        }

        return nm;

    }

    /**

     * Creates the keymap to use for the text component, and installs

     * any necessary bindings into it.  By default, the keymap is

     * shared between all instances of this type of TextUI. The

     * keymap has the name defined by the getKeymapName method.  If the

     * keymap is not found, then DEFAULT_KEYMAP from JTextComponent is used.

     * <p>

     * The set of bindings used to create the keymap is fetched

     * from the UIManager using a key formed by combining the

     * {@link #getPropertyPrefix} method

     * and the string <code>.keyBindings</code>.  The type is expected

     * to be <code>JTextComponent.KeyBinding[]</code>.

     *

     * @return the keymap

     * @see #getKeymapName

     * @see javax.swing.text.JTextComponent

     */

    protected Keymap createKeymap() {

        String nm = getKeymapName();

        Keymap map = JTextComponent.getKeymap(nm);

        if (map == null) {

            Keymap parent = JTextComponent.getKeymap(JTextComponent.DEFAULT_KEYMAP);

            map = JTextComponent.addKeymap(nm, parent);

            String prefix = getPropertyPrefix();

            Object o = DefaultLookup.get(editor, this,

                prefix + ".keyBindings");

            if ((o != null) && (o instanceof JTextComponent.KeyBinding[])) {

                JTextComponent.KeyBinding[] bindings = (JTextComponent.KeyBinding[]) o;

                JTextComponent.loadKeymap(map, bindings, getComponent().getActions());

            }

        }

        return map;

    }

    /**

     * This method gets called when a bound property is changed

     * on the associated JTextComponent.  This is a hook

     * which UI implementations may change to reflect how the

     * UI displays bound properties of JTextComponent subclasses.

     * This is implemented to do nothing (i.e. the response to

     * properties in JTextComponent itself are handled prior

     * to calling this method).

     *

     * This implementation updates the background of the text

     * component if the editable and/or enabled state changes.

     *

     * @param evt the property change event

     */

    protected void propertyChange(PropertyChangeEvent evt) {

        if (evt.getPropertyName().equals("editable") ||

                evt.getPropertyName().equals("enabled")) {

            updateBackground((JTextComponent)evt.getSource());

        } else if (evt.getPropertyName().equals("caretWidth")) {

            Object value = evt.getNewValue();

            if (value instanceof Number) {

                int width = ((Number) value).intValue();

                if (width >= 0) caretMargin = width;

            }

        }

    }

    /**

     * Updates the background of the text component based on whether the

     * text component is editable and/or enabled.

     *

     * @param c the JTextComponent that needs its background color updated

     */

    private void updateBackground(JTextComponent c) {

        // This is a temporary workaround.

        // This code does not correctly deal with Synth (Synth doesn't use

        // properties like this), nor does it deal with the situation where

        // the developer grabs the color from a JLabel and sets it as

        // the background for a JTextArea in all look and feels. The problem

        // scenario results if the Color obtained for the Label and TextArea

        // is ==, which is the case for the windows look and feel.

        // Until an appropriate solution is found, the code is being

        // reverted to what it was before the original fix.

        if (this instanceof SynthUI || (c instanceof JTextArea)) {

            return;

        }

        Color background = c.getBackground();

        if (background instanceof UIResource) {

            String prefix = getPropertyPrefix();

            Color disabledBG =

                DefaultLookup.getColor(c, this, prefix + ".disabledBackground", null);

            Color inactiveBG =

                DefaultLookup.getColor(c, this, prefix + ".inactiveBackground", null);

            Color bg =

                DefaultLookup.getColor(c, this, prefix + ".background", null);

            /* In an ideal situation, the following check would not be necessary

             * and we would replace the color any time the previous color was a

             * UIResouce. However, it turns out that there is existing code that

             * uses the following inadvisable pattern to turn a text area into

             * what appears to be a multi-line label:

             *

             * JLabel label = new JLabel();

             * JTextArea area = new JTextArea();

             * area.setBackground(label.getBackground());

             * area.setEditable(false);

             *

             * JLabel's default background is a UIResource. As such, just

             * checking for UIResource would have us always changing the

             * background away from what the developer wanted.

             *

             * Therefore, for JTextArea/JEditorPane, we'll additionally check

             * that the color we're about to replace matches one that was

             * installed by us from the UIDefaults.

             */

            if ((c instanceof JTextArea || c instanceof JEditorPane)

                    && background != disabledBG

                    && background != inactiveBG

                    && background != bg) {

                return;

            }

            Color newColor = null;

            if (!c.isEnabled()) {

                newColor = disabledBG;

            }

            if (newColor == null && !c.isEditable()) {

                newColor = inactiveBG;

            }

            if (newColor == null) {

                newColor = bg;

            }

            if (newColor != null && newColor != background) {

                c.setBackground(newColor);

            }

        }

    }

    /**

     * Gets the name used as a key to look up properties through the

     * UIManager.  This is used as a prefix to all the standard

     * text properties.

     *

     * @return the name

     */

    protected abstract String getPropertyPrefix();

    /**

     * Initializes component properties, such as font, foreground,

     * background, caret color, selection color, selected text color,

     * disabled text color, and border color.  The font, foreground, and

     * background properties are only set if their current value is either null

     * or a UIResource, other properties are set if the current

     * value is null.

     *

     * @see #uninstallDefaults

     * @see #installUI

     */

    protected void installDefaults()

    {

        String prefix = getPropertyPrefix();

        Font f = editor.getFont();

        if ((f == null) || (f instanceof UIResource)) {

            editor.setFont(UIManager.getFont(prefix + ".font"));

        }

        Color bg = editor.getBackground();

        if ((bg == null) || (bg instanceof UIResource)) {

            editor.setBackground(UIManager.getColor(prefix + ".background"));

        }

        Color fg = editor.getForeground();

        if ((fg == null) || (fg instanceof UIResource)) {

            editor.setForeground(UIManager.getColor(prefix + ".foreground"));

        }

        Color color = editor.getCaretColor();

        if ((color == null) || (color instanceof UIResource)) {

            editor.setCaretColor(UIManager.getColor(prefix + ".caretForeground"));

        }

        Color s = editor.getSelectionColor();

        if ((s == null) || (s instanceof UIResource)) {

            editor.setSelectionColor(UIManager.getColor(prefix + ".selectionBackground"));

        }

        Color sfg = editor.getSelectedTextColor();

        if ((sfg == null) || (sfg instanceof UIResource)) {

            editor.setSelectedTextColor(UIManager.getColor(prefix + ".selectionForeground"));

        }

        Color dfg = editor.getDisabledTextColor();

        if ((dfg == null) || (dfg instanceof UIResource)) {

            editor.setDisabledTextColor(UIManager.getColor(prefix + ".inactiveForeground"));

        }

        Border b = editor.getBorder();

        if ((b == null) || (b instanceof UIResource)) {

            editor.setBorder(UIManager.getBorder(prefix + ".border"));

        }

        Insets margin = editor.getMargin();

        if (margin == null || margin instanceof UIResource) {

            editor.setMargin(UIManager.getInsets(prefix + ".margin"));

        }

        updateCursor();

    }

    private void installDefaults2() {

        editor.addMouseListener(dragListener);

        editor.addMouseMotionListener(dragListener);

        String prefix = getPropertyPrefix();

        Caret caret = editor.getCaret();

        if (caret == null || caret instanceof UIResource) {

            caret = createCaret();

            editor.setCaret(caret);

            int rate = DefaultLookup.getInt(getComponent(), this, prefix + ".caretBlinkRate", 500);

            caret.setBlinkRate(rate);

        }

        Highlighter highlighter = editor.getHighlighter();

        if (highlighter == null || highlighter instanceof UIResource) {

            editor.setHighlighter(createHighlighter());

        }

        TransferHandler th = editor.getTransferHandler();

        if (th == null || th instanceof UIResource) {

            editor.setTransferHandler(getTransferHandler());

        }

    }

    /**

     * Sets the component properties that have not been explicitly overridden

     * to {@code null}.  A property is considered overridden if its current

     * value is not a {@code UIResource}.

     *

     * @see #installDefaults

     * @see #uninstallUI

     */

    protected void uninstallDefaults()

    {

        editor.removeMouseListener(dragListener);

        editor.removeMouseMotionListener(dragListener);

        if (editor.getCaretColor() instanceof UIResource) {

            editor.setCaretColor(null);

        }

        if (editor.getSelectionColor() instanceof UIResource) {

            editor.setSelectionColor(null);

        }

        if (editor.getDisabledTextColor() instanceof UIResource) {

            editor.setDisabledTextColor(null);

        }

        if (editor.getSelectedTextColor() instanceof UIResource) {

            editor.setSelectedTextColor(null);

        }

        if (editor.getBorder() instanceof UIResource) {

            editor.setBorder(null);

        }

        if (editor.getMargin() instanceof UIResource) {

            editor.setMargin(null);

        }

        if (editor.getCaret() instanceof UIResource) {

            editor.setCaret(null);

        }

        if (editor.getHighlighter() instanceof UIResource) {

            editor.setHighlighter(null);

        }

        if (editor.getTransferHandler() instanceof UIResource) {

            editor.setTransferHandler(null);

        }

        if (editor.getCursor() instanceof UIResource) {

            editor.setCursor(null);

        }

    }

    /**

     * Installs listeners for the UI.

     */

    protected void installListeners() {

    }

    /**

     * Uninstalls listeners for the UI.

     */

    protected void uninstallListeners() {

    }

    /**

     * Registers keyboard actions.

     */

    protected void installKeyboardActions() {

        // backward compatibility support... keymaps for the UI

        // are now installed in the more friendly input map.

        editor.setKeymap(createKeymap());

        InputMap km = getInputMap();

        if (km != null) {

            SwingUtilities.replaceUIInputMap(editor, JComponent.WHEN_FOCUSED,

                                             km);

        }

        ActionMap map = getActionMap();

        if (map != null) {

            SwingUtilities.replaceUIActionMap(editor, map);

        }

        updateFocusAcceleratorBinding(false);

    }

    /**

     * Get the InputMap to use for the UI.

     */

    InputMap getInputMap() {

        InputMap map = new InputMapUIResource();

        InputMap shared =

            (InputMap)DefaultLookup.get(editor, this,

            getPropertyPrefix() + ".focusInputMap");

        if (shared != null) {

            map.setParent(shared);

        }

        return map;

    }

    /**

     * Invoked when the focus accelerator changes, this will update the

     * key bindings as necessary.

     */

    void updateFocusAcceleratorBinding(boolean changed) {

        char accelerator = editor.getFocusAccelerator();

        if (changed || accelerator != '\0') {

            InputMap km = SwingUtilities.getUIInputMap

                        (editor, JComponent.WHEN_IN_FOCUSED_WINDOW);

            if (km == null && accelerator != '\0') {

                km = new ComponentInputMapUIResource(editor);

                SwingUtilities.replaceUIInputMap(editor, JComponent.

                                                 WHEN_IN_FOCUSED_WINDOW, km);

                ActionMap am = getActionMap();

                SwingUtilities.replaceUIActionMap(editor, am);

            }

            if (km != null) {

                km.clear();

                if (accelerator != '\0') {

                    km.put(KeyStroke.getKeyStroke(accelerator, BasicLookAndFeel.getFocusAcceleratorKeyMask()), "requestFocus");

                    km.put(KeyStroke.getKeyStroke(accelerator,

                            SwingUtilities2.setAltGraphMask(

                            BasicLookAndFeel.getFocusAcceleratorKeyMask())),

                            "requestFocus");

                }

            }

        }

    }