/*******************************************************************************

 * Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

 * All rights reserved. This program and the accompanying materials 

 * are made available under the terms of the Eclipse Public License v1.0

 * which accompanies this distribution, and is available at

 * http://www.eclipse.org/legal/epl-v10.html

 * 

 * Contributors:

 *     Nokia Corporation - initial implementation 

 *******************************************************************************/

package org.eclipse.swt.internal.qt;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.widgets.Event;

import org.eclipse.swt.widgets.Widget;

public class TextUtils extends Object {

    public static final int LINE_EDIT = 0;

    public static final int TEXT_EDIT = 1;

/**

 * @see Text.append

 * @param limit - if char count bigger than limit, text gets truncated

 * @param verifier - owner of verify listeners, can be null

 */

public static void append (int variant, int handle, String string, int limit, Widget verifier) {

    if (string == null) {

        SWT.error(SWT.ERROR_NULL_ARGUMENT);

    }

    int count = getCharCount(variant, handle);

    string = verify(variant, handle, string, verifier, limit, count, count);

    if (string == null) {

        return;   

    }

    if (variant == LINE_EDIT) {

        OS.QLineEdit_end(handle, false);

        OS.QLineEdit_insert(handle, string);

    }

    else {

        OS.QTextEdit_swt_append(handle, string);

    }

}

/**

 * @see Text.append

 */

public static void clearSelection (int variant, int handle) {

    if (variant == LINE_EDIT) {

        OS.QLineEdit_setCursorPosition(handle, OS.QLineEdit_cursorPosition(handle));

    } else {

        OS.QTextEdit_swt_clearSelection(handle);

    }

}

/**

 * @see Text.copy

 */

public static void copy (int variant, int handle) {

    if (variant == LINE_EDIT) {

        OS.QLineEdit_copy(handle);

    } else {

        OS.QTextEdit_copy(handle);

    }

}

/**

 * @see Text.cut

 * @param verifier - owner of verify listeners, can be null

 */

public static void cut (int variant, int handle, Widget verifier) {

    Point selection = getSelection(variant, handle);

    String string = verify(variant, handle, "", verifier, -1, 

        Math.min(selection.x, selection.y), Math.max(selection.x, selection.y));

    if (string == null) {

        return;

    }

    if (variant == LINE_EDIT) {

        OS.QLineEdit_cut(handle);

    } else {

        OS.QTextEdit_cut(handle);

    }

    if (!string.equals("")) {

        if (variant == LINE_EDIT) {

            OS.QLineEdit_insert(handle, string);

        } else {

            OS.QTextEdit_insertPlainText(handle, string);

        }

    }

}

/**

 * @see Text.getEditable

 */

public static boolean getReadOnly (int variant, int handle) {

    if (variant == TextUtils.LINE_EDIT) {

        return OS.QLineEdit_isReadOnly(handle);

    } else {

        return OS.QTextEdit_isReadOnly(handle);

    }

}

/**

 * @see Text.getSelection

 */

public static Point getSelection (int variant, int handle) {

    if (variant == LINE_EDIT) {

        int firstSelected = OS.QLineEdit_selectionStart(handle);

        if (firstSelected == -1) {

            int cursorPos = OS.QLineEdit_cursorPosition(handle);

            return new Point(cursorPos, cursorPos);

        }

        return new Point(firstSelected, firstSelected

                + OS.QLineEdit_selectedText(handle).length());

    } else {

        int start = OS.QTextEdit_swt_selectionStart(handle);

        int end = OS.QTextEdit_swt_selectionEnd(handle);

        return new Point(Math.min(start, end), Math.max(start, end));

    }

}

/**

 * @see Text.getSelectionText

 */

public static String getSelectionText (int variant, int handle) {

    if (variant == LINE_EDIT) {

        return OS.QLineEdit_selectedText(handle);

    } else {

        return OS.QTextEdit_swt_getSelectionText(handle);

    }

}

/**

 * @see Text.getCaretPosition

 */

public static int getCaretPosition (int variant, int handle) {

    if (variant == LINE_EDIT) {

        return OS.QLineEdit_cursorPosition(handle);

    } else {

        return OS.QTextEdit_swt_getCaretPosition(handle);

    }

}

/**

 * @see Text.getCharCount

 */

public static int getCharCount (int variant, int handle) {

    if (variant == LINE_EDIT) {

        return OS.QLineEdit_text(handle).length();

    } else {

        return OS.QTextEdit_swt_getCharCount(handle);

    }

}

/**

 * @see Text.getText

 */

public static String getText (int variant, int handle) {

    if (variant == LINE_EDIT) {

        return OS.QLineEdit_text(handle);

    } else {

        return OS.QTextEdit_toPlainText(handle);

    }

}

/**

 * @see Text.insert

 * @param limit - if char count bigger than limit, text gets truncated

 * @param verifier - owner of verify listeners, can be null

 */

public static void insert (int variant, int handle, String string, int limit, Widget verifier) {

    if (string == null) { 

        SWT.error (SWT.ERROR_NULL_ARGUMENT);

    }

    Point selection = getSelection(variant, handle);

    string = verify(variant, handle, string, verifier, limit, 

        Math.min(selection.x, selection.y), Math.max(selection.x, selection.y));

    if (string == null) {

        return;

    }

    if (variant == LINE_EDIT) {

        OS.QLineEdit_insert(handle, string);

    } else {

        OS.QTextEdit_insertPlainText(handle, string);

    }

}

/**

 * @see Text.insert

 * @param limit - if char count bigger than limit, text gets truncated

 * @param verifier - owner of verify listeners, can be null

 */

public static void paste (int variant, int handle, int limit, Widget verifier) {

    Point selection = getSelection(variant, handle);

    String string = verify(variant, handle, OS.QClipboard_text(), verifier, limit, 

        Math.min(selection.x, selection.y), Math.max(selection.x, selection.y));

    if (string == null) {

        return;

    }

    if (variant == LINE_EDIT) {

        OS.QLineEdit_insert(handle, string);

    } else {

        OS.QTextEdit_insertPlainText(handle, string);

    }

}

/**

 * @see Text.selectAll

 */

public static void selectAll (int variant, int handle) {

    if (variant == TextUtils.LINE_EDIT) {

        OS.QLineEdit_selectAll(handle);

    } else {

        OS.QTextEdit_swt_selectAll(handle);

    }

}

/**

 * @see Text.setEditable

 */

public static void setReadOnly (int variant, int handle, boolean readOnly) {

    if (variant == TextUtils.LINE_EDIT) {

        OS.QLineEdit_setReadOnly(handle, readOnly);

    } else {

        OS.QTextEdit_setReadOnly(handle, readOnly);

    }

}

/**

 * @see Text.setSelection

 */

public static void setSelection (int variant, int handle, int start, int end) {

    int length = getCharCount(variant, handle);

    start = Math.min(Math.max(0, start), length);

    end = Math.min(Math.max(0, end), length);

    if (variant == LINE_EDIT) {

        if(start == end) {

            OS.QLineEdit_deselect(handle);

            OS.QLineEdit_setCursorPosition(handle, start);

        } else {

            OS.QLineEdit_setSelection(handle, start, (end - start));

        }

    } else {

        OS.QTextEdit_swt_setCursorPosition(handle, start, true);

        OS.QTextEdit_swt_setCursorPosition(handle, end, false);

    }

}

/**

 * @see Text.setText

 * @param limit - if char count bigger than limit, text gets truncated

 * @param verifier - owner of verify listeners, can be null

 */

public static void setText (int variant, int handle, String string, int limit, Widget verifier) {

    if (string == null) {

        SWT.error(SWT.ERROR_NULL_ARGUMENT);

    }

    string = verify(variant, handle, string, verifier, limit, 0, getCharCount(variant, handle));

    if (string == null) {

        return;

    }

    if (variant == LINE_EDIT) {

        OS.QLineEdit_setText(handle, string);

        OS.QLineEdit_setCursorPosition(handle, 0);

    } else {

        OS.QTextEdit_setPlainText(handle, string);

    }

}

/**

 * @see Text.qt_event_keypress

 */

public static boolean handle_keypress(int variant, int handle, int key, 

    int modifier, int character, Event event, int textLimit, Widget verifier) {

    String origText = "" + (char) character;

    Point selection = getSelection(variant, handle);

    int start = selection.x;

    int end = selection.y;

    // keyboard shortcuts for paste

    if ((modifier == OS.QT_SHIFTMODIFIER && key == OS.QT_KEY_INSERT)

        || (modifier == OS.QT_CONTROLMODIFIER && key == OS.QT_KEY_V)) {

        origText = OS.QClipboard_text();

        if (origText == null || origText.equals("")) {

            return false;

        }

        event = null;

        // keyboard shortcuts for cut

    } else if ((modifier == OS.QT_SHIFTMODIFIER && key == OS.QT_KEY_DELETE)

        || (modifier == OS.QT_CONTROLMODIFIER && key == OS.QT_KEY_X)) {

        if (end == start) {

            return false;

        }

        event = null;

        origText = "";

        // Cancel ctrl + Del, ctrl + Backspace, alt + Bs and ctrl+k because these key bindings

        // behave differently in QLineEdit and in QTextEdit and making verifyEvents

        // to work fully reliably in all platforms is impossible.

    } else if (((modifier & OS.QT_CONTROLMODIFIER) != 0 && key == OS.QT_KEY_DELETE)

        || ((modifier & OS.QT_CONTROLMODIFIER) != 0 && key == OS.QT_KEY_BACKSPACE)

        || ((modifier & OS.QT_ALTMODIFIER) != 0 && key == OS.QT_KEY_BACKSPACE)

        || (modifier == OS.QT_CONTROLMODIFIER && key == OS.QT_KEY_K)) {

        return true;

        // Non-printable keys, return, backspace and delete

    } else if ((key & OS.QT_NONPRINTABLEKEYMASK) != 0) {

        switch (key) {

        case OS.QT_KEY_RETURN:

        case OS.QT_KEY_ENTER:

            if (variant == LINE_EDIT) {

                return false;

            }

            break;

        case OS.QT_KEY_BACKSPACE:

            if (end == start) {

                if (start == 0) {

                    return false;

                }

                --start;

            }

            origText = "";

            break;

        case OS.QT_KEY_DELETE:

            if (modifier != OS.QT_NOMODIFIER) {

                return false;

            }

            if (end == start) {

                if (end == getCharCount(variant, handle)) {

                    return false;

                }

                ++end;

            }

            origText = "";

            break;

        default:

            // No need to verify other non-printable characters

            return false;

        }

        // Don't verify key pressed that don't change the text. If

        // chararcter is smaller than the first printable ASCII char 

        // (= space), the text content is not modified.

        // For some unknown reason when ctrl+8 is pressed, character is

        // set Del. Ctrl+8 does not modify the text content anyway.

    } else if ((modifier & OS.QT_CONTROLMODIFIER) != 0 && ((char) character < ' ' || (char) character == SWT.DEL)) {

        return false;

    }

    String verifiedText = verify(variant, handle, origText, verifier, textLimit, start, end, event);

    if (verifiedText == null) {

        // Key event is not forwarded to native widget

        return true;

    } else if (verifiedText.equals(origText)) {

        return false;

    } else {

        setSelection(variant, handle, start, end);

        if (variant == LINE_EDIT) {

            OS.QLineEdit_insert(handle, verifiedText);

        } else {

            OS.QTextEdit_insertPlainText(handle, verifiedText);

        }

        // Key event is not forwarded to native widget

        return true;

    }

}

/**

 * Verify, limit, range

 */

public static String verify (int variant, int handle, String string, 

    Widget verifier, int limit, int start, int end) {

    return verify(variant, handle, string, verifier, limit, start, end, null);

}

/**

 * Verify, limit, range, key event

 */

public static String verify (int variant, int handle, String string, 

    Widget verifier, int limit, int start, int end, Event keyEvent) {

    if (string.length() == 0 && start == end) {

        return null;

    }

    if ((verifier != null) && ((verifier.getStyle() & SWT.SINGLE) != 0)) {

        string = string.replace('\n', '\u0020');//Replace with space

    }

    if (verifier != null) {

        Event event = new Event();

        event.text = string;

        event.start = start;

        event.end = end;

        if (keyEvent != null) {

            event.keyCode = keyEvent.keyCode;

            event.character = keyEvent.character;

            event.stateMask = keyEvent.stateMask;

        } else {

            event.keyCode = 0;

            event.character = 0;

            event.stateMask = 0;

        }

        verifier.notifyListeners(SWT.Verify, event);

        if (!event.doit || verifier.isDisposed()) {

            return null;

        }

        string = event.text;

    }

    if (limit > 0 && string.length() > 0) {

        int count = 0;

        if (variant == LINE_EDIT) {

            count = OS.QLineEdit_text(handle).length();

        }

        else {

            count = OS.QTextEdit_swt_getCharCount(handle); 

        }

        int spaceLeft = limit - count + (end - start);

        int endIdx = Math.min(Math.max(0, spaceLeft), string.length());

        string = string.substring(0, endIdx);

    }

    if (string == null || (string.length() == 0 && start == end)) {

        return null;

    }

    return string;

}

}