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

                      Uebungen zur Vorlesung
		  "Graphische Datenverarbeitung"
                       Sommersemester  1996

       Programm: drawkarte.c
       Autor:    Xiaowei Xu

       Programm zeichnet LandKarte von EU.

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

# include <stdio.h>
# include <stdlib.h>
# include <Xm/Xm.h>
# include <Xm/XmAll.h>
# include "Landkarte.h"

#define MAX_WIDTH	5069
#define MAX_HIGTH	5069
#define MIN_WIDTH	6
#define MIN_HIGTH	6

Widget		DrawAr;			/* Drawing Area */
XtAppContext	kontext;		/* Applikations-Umgebung */
GC		fensterGC, pixmapGC;	/* Graphik-Kontext fuer XDrawLine...*/
Display*	display;
Pixmap		GraphikPixmap = 0;

static char * fallbackRessourcen [] = {
	"Drawkarte.geometry: 750x500",
        "*drawingarea.background: white",
        "*drawingarea.foreground: black",
        NULL
} ;

void DrawLandkarte (int n, struct linesegment *segs,
			double s, Drawable w, GC g)
{
    int i ;

    for (i=0 ; i<n ; i++)
        XDrawLine (display, w, g,
        segs[i].x1*s, s-segs[i].y1*s, segs[i].x2*s, s-segs[i].y2*s) ;
}

void initGraphik (Widget widget)
{
        Dimension	w, h ;
	XGCValues	werte;       /* Struktur zum Setzen von GC-Attributen */

	XtVaGetValues (widget, XmNheight, &h, XmNwidth, &w, NULL) ;

	if (GraphikPixmap) {
                XFreeGC (display, pixmapGC) ;
                XFreePixmap (display, GraphikPixmap) ;
        }
        GraphikPixmap = XCreatePixmap (display, XtWindow (widget), w, h, 1) ;

        werte.foreground = 0 ;
        werte.background = 1 ;
        pixmapGC = XCreateGC (display, GraphikPixmap,
                              GCForeground | GCBackground, &werte) ;
        XFillRectangle (display, GraphikPixmap, pixmapGC, 0, 0, w, h) ;

        werte.foreground = 1 ;
        werte.background = 0 ;
        XChangeGC (display, pixmapGC, GCForeground | GCBackground, &werte) ;
}

void resizeCB (Widget widget, XtPointer dum2, XtPointer dum3)
{
	Dimension	w, h;
	double		scale ;

	XtVaGetValues (widget, XmNheight, &h, XmNwidth, &w, NULL) ;
	
	initGraphik (widget);
	scale = (double) ( w < h )? w : h ;
	DrawLandkarte (AnzahlLinien, lines, scale, GraphikPixmap, pixmapGC) ;
	XClearArea (display, XtWindow (widget), 0, 0, w, h, True) ;
}

void exposeCB (Widget widget, XtPointer clientDaten, XtPointer aufrufDaten)
{
        XmDrawingAreaCallbackStruct* DAinfos;

	/* Callback-Informationen mit Event-Struktur */
	DAinfos = (XmDrawingAreaCallbackStruct*)aufrufDaten;

	if (! GraphikPixmap)
	        resizeCB (widget, (XtPointer) 0, (XtPointer) 0) ;

	/* Im Expose-Event angegebenen Fenster-Ausschnitt 
	 * von Graphik-Bitmap ins Graphik-Fenster kopieren
	 */
	XCopyPlane (display, GraphikPixmap, XtWindow(widget), fensterGC,
		    DAinfos->event->xexpose.x, DAinfos->event->xexpose.y,
		    DAinfos->event->xexpose.width,
		    DAinfos->event->xexpose.height,
		    DAinfos->event->xexpose.x, DAinfos->event->xexpose.y,
		    1);
}

void ZoomPlusCB (Widget widget, XtPointer dum2, XtPointer dum3)
{
        Dimension	w, h;
        double		scale ;

        XtVaGetValues (DrawAr, XmNheight, &h, XmNwidth, &w, NULL) ;
	if ( ( w < MAX_WIDTH ) && ( h < MAX_HIGTH ) ) {
		XtVaSetValues (DrawAr, XmNx, 0, XmNy, 0, NULL) ;
		w = w+w/2;
		h = h+h/2;
		XtVaSetValues (DrawAr, XmNheight, h, XmNwidth, w, NULL) ;

        	initGraphik (DrawAr);
        	scale = (double) ( w < h )? w : h ;
        	DrawLandkarte (AnzahlLinien, lines, scale, GraphikPixmap, pixmapGC) ;
        	XClearArea (display, XtWindow (DrawAr), 0, 0, w, h, 0) ;
	}
	else
		XtAppWarning (kontext, "upper bound for zoom is reached!");
}

void ZoomMinusCB (Widget widget, XtPointer dum2, XtPointer dum3)
{
        Dimension	w, h;
        double		scale ;

        XtVaGetValues (DrawAr, XmNheight, &h, XmNwidth, &w, NULL) ;
	if ( ( w > MIN_WIDTH ) && ( h > MIN_HIGTH ) ) {
        	XtVaSetValues (DrawAr, XmNx, 0, XmNy, 0, NULL) ;
		w = w/2;
		h = h/2;
		XtVaSetValues (DrawAr, XmNheight, h, XmNwidth, w, NULL) ;

		initGraphik (DrawAr);
		scale = (double) ( w < h )? w : h ;
		DrawLandkarte (AnzahlLinien, lines, scale, GraphikPixmap, pixmapGC) ;
		XClearArea (display, XtWindow (DrawAr), 0, 0, w, h, 0) ;
	}
	else
		XtAppWarning (kontext, "lower bound for zoom is reached!");
}

void initAttributeBoxWidgets (Widget elternWidget)
{
	Widget		Zoom;
	Widget		ZoomPlus;
	Widget		ZoomMinus;

	Zoom =  XtVaCreateManagedWidget   ("Zoom",
					xmRowColumnWidgetClass, elternWidget,
					XmNpacking,     XmPACK_COLUMN,
					XmNnumColumns,  3,
					XmNorientation, XmVERTICAL,
					NULL);

	XtVaCreateManagedWidget ("Zoom:",
				xmLabelGadgetClass, Zoom, NULL);

	ZoomPlus = XtCreateManagedWidget ("Zoom +",xmPushButtonWidgetClass,
					Zoom, (Arg*)NULL, 0);
	ZoomMinus = XtCreateManagedWidget ("Zoom -",xmPushButtonWidgetClass,
					Zoom, (Arg*)NULL, 0);

	XtAddCallback (ZoomPlus, XmNactivateCallback, ZoomPlusCB, (XtPointer)NULL);
	XtAddCallback (ZoomMinus, XmNactivateCallback, ZoomMinusCB, (XtPointer)NULL);
}

void initGraphikWidget (Widget elternWidget)
{
	XGCValues     werte;

        DrawAr = XtVaCreateManagedWidget("drawingarea",
                                        xmDrawingAreaWidgetClass,
                                        elternWidget,
                                        XmNwidth, 500,
                                        XmNheight, 500,
                                        NULL) ;

        /* Fuer die Graphik-Ausgabe wird ein Graphik-Kontext (GC) erzeugt
           und mit den Vorder- und Hintergrundfarben der Drawing-Area-Widget
           besetzt. */
        XtVaGetValues (DrawAr, XmNforeground, &(werte.foreground),
                       XmNbackground, &(werte.background), NULL) ;
        fensterGC = XCreateGC (display, XtWindow (DrawAr),
            GCForeground | GCBackground, &werte) ;

        /* Callbacks registrieren. Der Resize-Callback darf erst
           nach XtRealizeWidget registriert werden */
        XtAddCallback (DrawAr, XmNexposeCallback, exposeCB, (XtPointer)NULL);
        XtAddCallback (DrawAr, XmNresizeCallback, resizeCB, (XtPointer)NULL);
}

Widget initForm (Widget elternWidget)
{
	Widget		formW;
	Widget		attributeBoxW;
	Widget		scrollW;
	Arg		args[10];
	Cardinal	n;

	formW = XtCreateManagedWidget ("form", xmFormWidgetClass,
					elternWidget, (Arg*)NULL, 0);

	n = 0;
	XtSetArg (args[n], XmNtopAttachment,  XmATTACH_WIDGET);  n++;
	XtSetArg (args[n], XmNleftAttachment, XmATTACH_FORM);    n++;
	attributeBoxW = XtCreateManagedWidget ("attributeBox",
						xmRowColumnWidgetClass,
						formW, args, n);

	initAttributeBoxWidgets (attributeBoxW);

	n = 0;
	XtSetArg (args[n], XmNtopAttachment,    XmATTACH_WIDGET);   n++;
	XtSetArg (args[n], XmNleftAttachment,   XmATTACH_WIDGET);   n++;
	XtSetArg (args[n], XmNleftWidget,       attributeBoxW);     n++;
	XtSetArg (args[n], XmNrightAttachment,  XmATTACH_FORM);     n++;
	XtSetArg (args[n], XmNbottomAttachment, XmATTACH_FORM);     n++;
	XtSetArg (args[n], XmNwidth, 500);     n++;
	XtSetArg (args[n], XmNheight, 500);     n++;
	XtSetArg (args[n], XmNscrollingPolicy, XmAUTOMATIC);     n++;
	scrollW = XtCreateManagedWidget ("scrolledGraphik",
                                     xmScrolledWindowWidgetClass,
                                     formW, args, n);

	initGraphikWidget (scrollW);

	return formW;
}

void initWidgets (Widget rtW)
{
	Widget        mainW;
	Widget        formW;
	XGCValues     werte;       /* Struktur zum Setzen von GC-Attributen */

	mainW = XtCreateManagedWidget ("main", xmMainWindowWidgetClass,
					rtW, (Arg*)NULL, 0);

	formW = initForm (mainW);

	XmMainWindowSetAreas (mainW, (Widget)NULL, (Widget)NULL,
				(Widget)NULL, (Widget)NULL, formW);
}

main (int argc, char ** argv)
{
	Widget		applShell;

	applShell = XtAppInitialize (&kontext, "Drawkarte",
				     (XrmOptionDescRec*)NULL, 0,
				     &argc, argv, fallbackRessourcen,
				     (Arg*)NULL, 0);

        display = XtDisplay (applShell);
        XtRealizeWidget (applShell);

	initWidgets (applShell);

	XtAppMainLoop (kontext);
}