/*******************************************************************************
 * Copyright (c) 2000, 2007 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *     Chriss Gross (schtoo@schtoo.com) - fix for 61670
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.ui.internal.forms.widgets.FormUtil;


// import com.ibm.icu.text.BreakIterator;

import dwt.DWT;
import dwt.custom.ScrolledComposite;
import dwt.events.MouseEvent;
import dwt.graphics.Device;
import dwt.graphics.FontMetrics;
import dwt.graphics.GC;
import dwt.graphics.Image;
import dwt.graphics.ImageData;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;
import dwt.layout.GridData;
import dwt.widgets.Combo;
import dwt.widgets.Composite;
import dwt.widgets.Control;
import dwt.widgets.Label;
import dwt.widgets.Layout;
import dwt.widgets.ScrollBar;
import dwt.widgets.Text;
import dwtx.ui.forms.widgets.ColumnLayout;
import dwtx.ui.forms.widgets.Form;
import dwtx.ui.forms.widgets.FormText;
import dwtx.ui.forms.widgets.FormToolkit;
import dwtx.ui.forms.widgets.ILayoutExtension;

import dwt.dwthelper.utils;

import  dwtx.dwtxhelper.BreakIterator;
// import mango.icu.UString;
// import mango.icu.ULocale;
// import mango.icu.UBreakIterator;

public class FormUtil {

    public static const String PLUGIN_ID = "dwtx.ui.forms"; //$NON-NLS-1$

    static const int H_SCROLL_INCREMENT = 5;

    static const int V_SCROLL_INCREMENT = 64;

    public static const String DEBUG = PLUGIN_ID ~ "/debug"; //$NON-NLS-1$

    public static const String DEBUG_TEXT = DEBUG ~ "/text"; //$NON-NLS-1$
    public static const String DEBUG_TEXTSIZE = DEBUG ~ "/textsize"; //$NON-NLS-1$

    public static const String DEBUG_FOCUS = DEBUG ~ "/focus"; //$NON-NLS-1$

    public static const String FOCUS_SCROLLING = "focusScrolling"; //$NON-NLS-1$

    public static const String IGNORE_BODY = "__ignore_body__"; //$NON-NLS-1$

    public static Text createText(Composite parent, String label,
            FormToolkit factory) {
        return createText(parent, label, factory, 1);
    }

    public static Text createText(Composite parent, String label,
            FormToolkit factory, int span) {
        factory.createLabel(parent, label);
        Text text = factory.createText(parent, ""); //$NON-NLS-1$
        int hfill = span is 1 ? GridData.FILL_HORIZONTAL
                : GridData.HORIZONTAL_ALIGN_FILL;
        GridData gd = new GridData(hfill | GridData.VERTICAL_ALIGN_CENTER);
        gd.horizontalSpan = span;
        text.setLayoutData(gd);
        return text;
    }

    public static Text createText(Composite parent, String label,
            FormToolkit factory, int span, int style) {
        Label l = factory.createLabel(parent, label);
        if ((style & DWT.MULTI) !is 0) {
            GridData gd = new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
            l.setLayoutData(gd);
        }
        Text text = factory.createText(parent, "", style); //$NON-NLS-1$
        int hfill = span is 1 ? GridData.FILL_HORIZONTAL
                : GridData.HORIZONTAL_ALIGN_FILL;
        GridData gd = new GridData(hfill | GridData.VERTICAL_ALIGN_CENTER);
        gd.horizontalSpan = span;
        text.setLayoutData(gd);
        return text;
    }

    public static Text createText(Composite parent, FormToolkit factory,
            int span) {
        Text text = factory.createText(parent, ""); //$NON-NLS-1$
        int hfill = span is 1 ? GridData.FILL_HORIZONTAL
                : GridData.HORIZONTAL_ALIGN_FILL;
        GridData gd = new GridData(hfill | GridData.VERTICAL_ALIGN_CENTER);
        gd.horizontalSpan = span;
        text.setLayoutData(gd);
        return text;
    }

    public static int computeMinimumWidth(GC gc, String text) {
        auto wb =  UBreakIterator.openWordIterator( ULocale.Default, text );
        scope(exit) wb.close();
        int last = 0;
        int width = 0;

        for (int loc = wb.first(); loc !is UBreakIterator.DONE; loc = wb.next()) {
            String word = text.substring(last, loc);
            Point extent = gc.textExtent(word);
            width = Math.max(width, extent.x);
            last = loc;
        }
        String lastWord = text.substring(last);
        Point extent = gc.textExtent(lastWord);
        width = Math.max(width, extent.x);
        return width;
    }

    public static Point computeWrapSize(GC gc, String text, int wHint) {
        auto wb =  UBreakIterator.openWordIterator( ULocale.Default, text );
        scope(exit) wb.close();
        FontMetrics fm = gc.getFontMetrics();
        int lineHeight = fm.getHeight();

        int saved = 0;
        int last = 0;
        int height = lineHeight;
        int maxWidth = 0;
        for (int loc = wb.first(); loc !is UBreakIterator.DONE; loc = wb.next()) {
            String word = text.substring(saved, loc);
            Point extent = gc.textExtent(word);
            if (extent.x > wHint) {
                // overflow
                saved = last;
                height += extent.y;
                // switch to current word so maxWidth will accommodate very long single words
                word = text.substring(last, loc);
                extent = gc.textExtent(word);
            }
            maxWidth = Math.max(maxWidth, extent.x);
            last = loc;
        }
        /*
         * Correct the height attribute in case it was calculated wrong due to wHint being less than maxWidth.
         * The recursive call proved to be the only thing that worked in all cases. Some attempts can be made
         * to estimate the height, but the algorithm needs to be run again to be sure.
         */
        if (maxWidth > wHint)
            return computeWrapSize(gc, text, maxWidth);
        return new Point(maxWidth, height);
    }

    public static void paintWrapText(GC gc, String text, Rectangle bounds) {
        paintWrapText(gc, text, bounds, false);
    }

    public static void paintWrapText(GC gc, String text, Rectangle bounds,
            bool underline) {
        auto wb =  UBreakIterator.openWordIterator( ULocale.Default, text );
        scope(exit) wb.close();
        FontMetrics fm = gc.getFontMetrics();
        int lineHeight = fm.getHeight();
        int descent = fm.getDescent();

        int saved = 0;
        int last = 0;
        int y = bounds.y;
        int width = bounds.width;

        for (int loc = wb.first(); loc !is UBreakIterator.DONE; loc = wb.next()) {
            String line = text.substring(saved, loc);
            Point extent = gc.textExtent(line);

            if (extent.x > width) {
                // overflow
                String prevLine = text.substring(saved, last);
                gc.drawText(prevLine, bounds.x, y, true);
                if (underline) {
                    Point prevExtent = gc.textExtent(prevLine);
                    int lineY = y + lineHeight - descent + 1;
                    gc
                            .drawLine(bounds.x, lineY, bounds.x + prevExtent.x,
                                    lineY);
                }

                saved = last;
                y += lineHeight;
            }
            last = loc;
        }
        // paint the last line
        String lastLine = text.substring(saved, last);
        gc.drawText(lastLine, bounds.x, y, true);
        if (underline) {
            int lineY = y + lineHeight - descent + 1;
            Point lastExtent = gc.textExtent(lastLine);
            gc.drawLine(bounds.x, lineY, bounds.x + lastExtent.x, lineY);
        }
    }

    public static ScrolledComposite getScrolledComposite(Control c) {
        Composite parent = c.getParent();

        while (parent !is null) {
            if ( auto sc = cast(ScrolledComposite)parent ) {
                return sc;
            }
            parent = parent.getParent();
        }
        return null;
    }

    public static void ensureVisible(Control c) {
        ScrolledComposite scomp = getScrolledComposite(c);
        if (scomp !is null) {
            Object data = scomp.getData(FOCUS_SCROLLING);
            if (data is null || !data.opEquals(Boolean.FALSE))
                FormUtil.ensureVisible(scomp, c);
        }
    }

    public static void ensureVisible(ScrolledComposite scomp, Control control) {
        // if the control is a FormText we do not need to scroll since it will
        // ensure visibility of its segments as necessary
        if ( auto ft = cast(FormText)control )
            return;
        Point controlSize = control.getSize();
        Point controlOrigin = getControlLocation(scomp, control);
        ensureVisible(scomp, controlOrigin, controlSize);
    }

    public static void ensureVisible(ScrolledComposite scomp,
            Point controlOrigin, Point controlSize) {
        Rectangle area = scomp.getClientArea();
        Point scompOrigin = scomp.getOrigin();

        int x = scompOrigin.x;
        int y = scompOrigin.y;

        // horizontal right, but only if the control is smaller
        // than the client area
        if (controlSize.x < area.width
                && (controlOrigin.x + controlSize.x > scompOrigin.x
                        + area.width)) {
            x = controlOrigin.x + controlSize.x - area.width;
        }
        // horizontal left - make sure the left edge of
        // the control is showing
        if (controlOrigin.x < x) {
            if (controlSize.x < area.width)
                x = controlOrigin.x + controlSize.x - area.width;
            else
                x = controlOrigin.x;
        }
        // vertical bottom
        if (controlSize.y < area.height
                && (controlOrigin.y + controlSize.y > scompOrigin.y
                        + area.height)) {
            y = controlOrigin.y + controlSize.y - area.height;
        }
        // vertical top - make sure the top of
        // the control is showing
        if (controlOrigin.y < y) {
            if (controlSize.y < area.height)
                y = controlOrigin.y + controlSize.y - area.height;
            else
                y = controlOrigin.y;
        }

        if (scompOrigin.x !is x || scompOrigin.y !is y) {
            // scroll to reveal
            scomp.setOrigin(x, y);
        }
    }

    public static void ensureVisible(ScrolledComposite scomp, Control control,
            MouseEvent e) {
        Point controlOrigin = getControlLocation(scomp, control);
        int rX = controlOrigin.x + e.x;
        int rY = controlOrigin.y + e.y;
        Rectangle area = scomp.getClientArea();
        Point scompOrigin = scomp.getOrigin();

        int x = scompOrigin.x;
        int y = scompOrigin.y;
        // System.out.println("Ensure: area="+area+", origin="+scompOrigin+",
        // cloc="+controlOrigin+", csize="+controlSize+", x="+x+", y="+y);

        // horizontal right
        if (rX > scompOrigin.x + area.width) {
            x = rX - area.width;
        }
        // horizontal left
        else if (rX < x) {
            x = rX;
        }
        // vertical bottom
        if (rY > scompOrigin.y + area.height) {
            y = rY - area.height;
        }
        // vertical top
        else if (rY < y) {
            y = rY;
        }

        if (scompOrigin.x !is x || scompOrigin.y !is y) {
            // scroll to reveal
            scomp.setOrigin(x, y);
        }
    }

    public static Point getControlLocation(ScrolledComposite scomp,
            Control control) {
        int x = 0;
        int y = 0;
        Control content = scomp.getContent();
        Control currentControl = control;
        for (;;) {
            if (currentControl is content)
                break;
            Point location = currentControl.getLocation();
            // if (location.x > 0)
            // x += location.x;
            // if (location.y > 0)
            // y += location.y;
            x += location.x;
            y += location.y;
            currentControl = currentControl.getParent();
        }
        return new Point(x, y);
    }

    static void scrollVertical(ScrolledComposite scomp, bool up) {
        scroll(scomp, 0, up ? -V_SCROLL_INCREMENT : V_SCROLL_INCREMENT);
    }

    static void scrollHorizontal(ScrolledComposite scomp, bool left) {
        scroll(scomp, left ? -H_SCROLL_INCREMENT : H_SCROLL_INCREMENT, 0);
    }

    static void scrollPage(ScrolledComposite scomp, bool up) {
        Rectangle clientArea = scomp.getClientArea();
        int increment = up ? -clientArea.height : clientArea.height;
        scroll(scomp, 0, increment);
    }

    static void scroll(ScrolledComposite scomp, int xoffset, int yoffset) {
        Point origin = scomp.getOrigin();
        Point contentSize = scomp.getContent().getSize();
        int xorigin = origin.x + xoffset;
        int yorigin = origin.y + yoffset;
        xorigin = Math.max(xorigin, 0);
        xorigin = Math.min(xorigin, contentSize.x - 1);
        yorigin = Math.max(yorigin, 0);
        yorigin = Math.min(yorigin, contentSize.y - 1);
        scomp.setOrigin(xorigin, yorigin);
    }

    public static void updatePageIncrement(ScrolledComposite scomp) {
        ScrollBar vbar = scomp.getVerticalBar();
        if (vbar !is null) {
            Rectangle clientArea = scomp.getClientArea();
            int increment = clientArea.height - 5;
            vbar.setPageIncrement(increment);
        }
        ScrollBar hbar = scomp.getHorizontalBar();
        if (hbar !is null) {
            Rectangle clientArea = scomp.getClientArea();
            int increment = clientArea.width - 5;
            hbar.setPageIncrement(increment);
        }
    }

    public static void processKey(int keyCode, Control c) {
        ScrolledComposite scomp = FormUtil.getScrolledComposite(c);
        if (scomp !is null) {
            if (null !is cast(Combo)c )
                return;
            switch (keyCode) {
            case DWT.ARROW_DOWN:
                if (scomp.getData("novarrows") is null) //$NON-NLS-1$
                    FormUtil.scrollVertical(scomp, false);
                break;
            case DWT.ARROW_UP:
                if (scomp.getData("novarrows") is null) //$NON-NLS-1$
                    FormUtil.scrollVertical(scomp, true);
                break;
            case DWT.ARROW_LEFT:
                FormUtil.scrollHorizontal(scomp, true);
                break;
            case DWT.ARROW_RIGHT:
                FormUtil.scrollHorizontal(scomp, false);
                break;
            case DWT.PAGE_UP:
                FormUtil.scrollPage(scomp, true);
                break;
            case DWT.PAGE_DOWN:
                FormUtil.scrollPage(scomp, false);
                break;
            default:
            }
        }
    }

    public static bool isWrapControl(Control c) {
        if ((c.getStyle() & DWT.WRAP) !is 0)
            return true;
        if (auto comp = cast(Composite)c ) {
            return ( null !is cast(ILayoutExtension)( comp.getLayout() ));
        }
        return false;
    }

    public static int getWidthHint(int wHint, Control c) {
        bool wrap = isWrapControl(c);
        return wrap ? wHint : DWT.DEFAULT;
    }

    public static int getHeightHint(int hHint, Control c) {
        if ( auto comp = cast(Composite)c ) {
            Layout layout = comp.getLayout();
            if (null !is cast(ColumnLayout)layout )
                return hHint;
        }
        return DWT.DEFAULT;
    }

    public static int computeMinimumWidth(Control c, bool changed) {
        if ( auto comp = cast(Composite)c ) {
            Layout layout = comp.getLayout();
            if ( auto le = cast(ILayoutExtension)layout )
                return le.computeMinimumWidth(
                        comp, changed);
        }
        return c.computeSize(FormUtil.getWidthHint(5, c), DWT.DEFAULT, changed).x;
    }

    public static int computeMaximumWidth(Control c, bool changed) {
        if ( auto comp = cast(Composite)c ) {
            Layout layout = comp.getLayout();
            if ( auto le = cast(ILayoutExtension)layout )
                return le.computeMaximumWidth(
                        comp, changed);
        }
        return c.computeSize(DWT.DEFAULT, DWT.DEFAULT, changed).x;
    }

    public static Form getForm(Control c) {
        Composite parent = c.getParent();
        while (parent !is null) {
            if ( auto frm = cast(Form)parent ) {
                return frm;
            }
            parent = parent.getParent();
        }
        return null;
    }

    public static Image createAlphaMashImage(Device device, Image srcImage) {
        Rectangle bounds = srcImage.getBounds();
        int alpha = 0;
        int calpha = 0;
        ImageData data = srcImage.getImageData();
        // Create a new image with alpha values alternating
        // between fully transparent (0) and fully opaque (255).
        // This image will show the background through the
        // transparent pixels.
        for (int i = 0; i < bounds.height; i++) {
            // scan line
            alpha = calpha;
            for (int j = 0; j < bounds.width; j++) {
                // column
                data.setAlpha(j, i, alpha);
                alpha = alpha is 255 ? 0 : 255;
            }
            calpha = calpha is 255 ? 0 : 255;
        }
        return new Image(device, data);
    }

    public static bool mnemonicMatch(String text, dchar key) {
        char mnemonic = findMnemonic(text);
        if (mnemonic is '\0')
            return false;
        return CharacterToUpper(key) is CharacterToUpper(mnemonic);
    }

    private static char findMnemonic(String string) {
        int index = 0;
        int length = string.length;
        do {
            while (index < length && string.charAt(index) !is '&')
                index++;
            if (++index >= length)
                return '\0';
            if (string.charAt(index) !is '&')
                return string.charAt(index);
            index++;
        } while (index < length);
        return '\0';
    }

    public static void setFocusScrollingEnabled(Control c, bool enabled) {
        ScrolledComposite scomp = null;

        if ( auto sc = cast(ScrolledComposite)c )
            scomp = sc;
        else
            scomp = getScrolledComposite(c);
        if (scomp !is null)
            scomp.setData(FormUtil.FOCUS_SCROLLING, enabled ? null : Boolean.FALSE);
    }

    public static void setAntialias(GC gc, int style) {
        if (!gc.getAdvanced()) {
            gc.setAdvanced(true);
            if (!gc.getAdvanced())
                return;
        }
        gc.setAntialias(style);
    }
}