/*

 * Copyright (c) 1997, 2006, 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.text;

import sun.swing.SwingUtilities2;

import java.awt.*;

import javax.swing.JPasswordField;

/**

 * Implements a View suitable for use in JPasswordField

 * UI implementations.  This is basically a field ui that

 * renders its contents as the echo character specified

 * in the associated component (if it can narrow the

 * component to a JPasswordField).

 *

 * @author  Timothy Prinzing

 * @see     View

 */

public class PasswordView extends FieldView {

    /**

     * Constructs a new view wrapped on an element.

     *

     * @param elem the element

     */

    public PasswordView(Element elem) {

        super(elem);

    }

    /**

     * Renders the given range in the model as normal unselected

     * text.  This sets the foreground color and echos the characters

     * using the value returned by getEchoChar().

     *

     * @param g the graphics context

     * @param x the starting X coordinate >= 0

     * @param y the starting Y coordinate >= 0

     * @param p0 the starting offset in the model >= 0

     * @param p1 the ending offset in the model >= p0

     * @return the X location of the end of the range >= 0

     * @exception BadLocationException if p0 or p1 are out of range

     */

    protected int drawUnselectedText(Graphics g, int x, int y,

                                     int p0, int p1) throws BadLocationException {

        Container c = getContainer();

        if (c instanceof JPasswordField) {

            JPasswordField f = (JPasswordField) c;

            if (! f.echoCharIsSet()) {

                return super.drawUnselectedText(g, x, y, p0, p1);

            }

            if (f.isEnabled()) {

                g.setColor(f.getForeground());

            }

            else {

                g.setColor(f.getDisabledTextColor());

            }

            char echoChar = f.getEchoChar();

            int n = p1 - p0;

            for (int i = 0; i < n; i++) {

                x = drawEchoCharacter(g, x, y, echoChar);

            }

        }

        return x;

    }

    /**

     * Renders the given range in the model as selected text.  This

     * is implemented to render the text in the color specified in

     * the hosting component.  It assumes the highlighter will render

     * the selected background.  Uses the result of getEchoChar() to

     * display the characters.

     *

     * @param g the graphics context

     * @param x the starting X coordinate >= 0

     * @param y the starting Y coordinate >= 0

     * @param p0 the starting offset in the model >= 0

     * @param p1 the ending offset in the model >= p0

     * @return the X location of the end of the range >= 0

     * @exception BadLocationException if p0 or p1 are out of range

     */

    protected int drawSelectedText(Graphics g, int x,

                                   int y, int p0, int p1) throws BadLocationException {

        g.setColor(selected);

        Container c = getContainer();

        if (c instanceof JPasswordField) {

            JPasswordField f = (JPasswordField) c;

            if (! f.echoCharIsSet()) {

                return super.drawSelectedText(g, x, y, p0, p1);

            }

            char echoChar = f.getEchoChar();

            int n = p1 - p0;

            for (int i = 0; i < n; i++) {

                x = drawEchoCharacter(g, x, y, echoChar);

            }

        }

        return x;

    }

    /**

     * Renders the echo character, or whatever graphic should be used

     * to display the password characters.  The color in the Graphics

     * object is set to the appropriate foreground color for selected

     * or unselected text.

     *

     * @param g the graphics context

     * @param x the starting X coordinate >= 0

     * @param y the starting Y coordinate >= 0

     * @param c the echo character

     * @return the updated X position >= 0

     */

    protected int drawEchoCharacter(Graphics g, int x, int y, char c) {

        ONE[0] = c;

        SwingUtilities2.drawChars(Utilities.getJComponent(this),

                                  g, ONE, 0, 1, x, y);

        return x + g.getFontMetrics().charWidth(c);

    }

    /**

     * Provides a mapping from the document model coordinate space

     * to the coordinate space of the view mapped to it.

     *

     * @param pos the position to convert >= 0

     * @param a the allocated region to render into

     * @return the bounding box of the given position

     * @exception BadLocationException  if the given position does not

     *   represent a valid location in the associated document

     * @see View#modelToView

     */

    public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {

        Container c = getContainer();

        if (c instanceof JPasswordField) {

            JPasswordField f = (JPasswordField) c;

            if (! f.echoCharIsSet()) {

                return super.modelToView(pos, a, b);

            }

            char echoChar = f.getEchoChar();

            FontMetrics m = f.getFontMetrics(f.getFont());

            Rectangle alloc = adjustAllocation(a).getBounds();

            int dx = (pos - getStartOffset()) * m.charWidth(echoChar);

            alloc.x += dx;

            alloc.width = 1;

            return alloc;

        }

        return null;

    }

    /**

     * Provides a mapping from the view coordinate space to the logical

     * coordinate space of the model.

     *

     * @param fx the X coordinate >= 0.0f

     * @param fy the Y coordinate >= 0.0f

     * @param a the allocated region to render into

     * @return the location within the model that best represents the

     *  given point in the view

     * @see View#viewToModel

     */

    public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias) {

        bias[0] = Position.Bias.Forward;

        int n = 0;

        Container c = getContainer();

        if (c instanceof JPasswordField) {

            JPasswordField f = (JPasswordField) c;

            if (! f.echoCharIsSet()) {

                return super.viewToModel(fx, fy, a, bias);

            }

            char echoChar = f.getEchoChar();

            int charWidth = f.getFontMetrics(f.getFont()).charWidth(echoChar);

            a = adjustAllocation(a);

            Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a :

                              a.getBounds();

            n = (charWidth > 0 ?

                 ((int)fx - alloc.x) / charWidth : Integer.MAX_VALUE);

            if (n < 0) {

                n = 0;

            }

            else if (n > (getStartOffset() + getDocument().getLength())) {

                n = getDocument().getLength() - getStartOffset();

            }

        }

        return getStartOffset() + n;

    }

    /**

     * Determines the preferred span for this view along an

     * axis.

     *

     * @param axis may be either View.X_AXIS or View.Y_AXIS

     * @return   the span the view would like to be rendered into >= 0.

     *           Typically the view is told to render into the span

     *           that is returned, although there is no guarantee.

     *           The parent may choose to resize or break the view.

     */

    public float getPreferredSpan(int axis) {

        switch (axis) {

        case View.X_AXIS:

            Container c = getContainer();

            if (c instanceof JPasswordField) {

                JPasswordField f = (JPasswordField) c;

                if (f.echoCharIsSet()) {

                    char echoChar = f.getEchoChar();

                    FontMetrics m = f.getFontMetrics(f.getFont());

                    Document doc = getDocument();

                    return m.charWidth(echoChar) * getDocument().getLength();

                }

            }

        }

        return super.getPreferredSpan(axis);

    }

    static char[] ONE = new char[1];

}