test5.c

安装DDD之前

/* $Header: /cvsroot/lesstif/lesstif/test/Xm/scrolledwindow/test5.c,v 1.4 2001/05/23 14:30:30 amai Exp $
** Generated by X-Designer 
** autopan
*/
/*
**LIBS: -lXm -lXt -lX11
*/

#include <X11/Xatom.h>
#include <X11/Intrinsic.h>
#include <X11/Shell.h>

#include <Xm/Xm.h>
#include <Xm/DialogS.h>
#include <Xm/DrawingA.h>
#include <Xm/Form.h>
#include <Xm/PushB.h>
#include <Xm/ScrollBar.h>
#include <Xm/ScrolledW.h>

#include <Xm/Xm.h>
#include <stdio.h>

typedef struct canvas_s {
	Widget          da;
	Widget          hsb;
	Widget          vsb;
	int             width, height, x_offset, y_offset;
	GC              gc;
	/* New fields for autopanning */
	int             v_scroll_direction;
	int             h_scroll_direction;
	XtIntervalId    timer;
}               canvas_t, *canvas_p;
extern Widget create_appshell();

/*
 * *LIBS: -lXm -lXt -lX11
 */

extern void     register_actions();
extern void     expand();
extern void     expose();
extern void     graphics_expose();
extern void     resize();
extern void     hsb_changed();
extern void     vsb_changed();
extern void	create_gc();

extern void adjust_size();

void
expand(w, client_data, call_data)
	Widget          w;
	XtPointer       client_data;
	XtPointer       call_data;
{
	/* Double the size of the (notional) canvas */
	canvas_p canvas = (canvas_p)client_data;
	canvas->width=2*canvas->width;
	canvas->height=2*canvas->height;
	adjust_size(canvas);
	/*
	* Generate expose event for entire window (strictly
	* only needed if XmDrawingArea is larger than canvas.
	*/
	XClearArea(XtDisplay(canvas->da), XtWindow(canvas->da),
		   0, 0, 0, 0, True);
}
static void
set_no_clip(canvas)
	canvas_p        canvas;
{
	XSetClipMask(XtDisplay(canvas->da), canvas->gc, None);
}

/*
 * XmScrollBar callbacks copy an area from the window to itself.
 */

void
hsb_changed(w, client_data, call_data)
	Widget          w;
	XtPointer       client_data;
	XtPointer       call_data;
{
	canvas_p        canvas = (canvas_p) client_data;
	int             slider_size;
	int             pixels_to_lose;
	Boolean         positive;
	Display        *display = XtDisplay(canvas->da);
	Window          window = XtWindow(canvas->da);
	int             new_value =
	((XmScrollBarCallbackStruct *) call_data)->value;
	XEvent          event;

	XSync(display, False);
	while (XCheckWindowEvent(display, window, ExposureMask, &event))
		XtDispatchEvent(&event);

	if (canvas->x_offset == new_value)
		return;
	XtVaGetValues(canvas->hsb, XmNsliderSize, &slider_size, NULL);
	/* Work out how far (and in which direction) we need to scroll */
	if ((positive = (new_value > canvas->x_offset)))
		pixels_to_lose = new_value - canvas->x_offset;
	else
		pixels_to_lose = canvas->x_offset - new_value;
	canvas->x_offset = new_value;
	if (pixels_to_lose >= slider_size)
		/* Scrolling more than a page, nothing worth copying */
		XClearArea(display, window, 0, 0, 0, 0, True);
	else {
		/* Copy useful section, and expose revealed section */
		Dimension       width, height;

		XtVaGetValues(canvas->da, XmNwidth, &width,
			      XmNheight, &height, NULL);
		set_no_clip(canvas);
		if (positive) {
			XCopyArea(display, window, window, canvas->gc,
				  pixels_to_lose, 0, width - pixels_to_lose, height, 0, 0);
			XClearArea(display, window,
				   width - pixels_to_lose, 0, pixels_to_lose, height, True);
		} else {
			XCopyArea(display, window, window, canvas->gc,
				  0, 0, width - pixels_to_lose, height, pixels_to_lose, 0);
			XClearArea(display, window, 0, 0, pixels_to_lose, height, True);
		}
	}
}

void 
vsb_changed(w, client_data, call_data)
	Widget          w;
	XtPointer       client_data;
	XtPointer       call_data;
{
	canvas_p        canvas = (canvas_p) client_data;
	int             slider_size;
	int             pixels_to_lose;
	Boolean         positive;
	XEvent          event;
	Display        *display = XtDisplay(canvas->da);
	Window          window = XtWindow(canvas->da);
	int             new_offset =
	((XmScrollBarCallbackStruct *) call_data)->value * 20;

	/*
	 * Basically the same code as before, but converts from
	 * scrollbar units (lines) to pixels.
	 */
	if (canvas->y_offset == new_offset)
		return;
	XSync(display, False);
	while (XCheckWindowEvent(display, window, ExposureMask, &event))
		XtDispatchEvent(&event);
	XtVaGetValues(canvas->vsb, XmNsliderSize, &slider_size, NULL);
	if ((positive = (new_offset > canvas->y_offset)))
		pixels_to_lose = new_offset - canvas->y_offset;
	else
		pixels_to_lose = canvas->y_offset - new_offset;
	canvas->y_offset = new_offset;
	if (pixels_to_lose >= slider_size * 20)
		/* Scrolling more than a page, nothing worth copying */
		XClearArea(display, window, 0, 0, 0, 0, True);
	else {
		/* Copy useful section, and expose revealed section */
		Dimension       width, height;

		XtVaGetValues(canvas->da, XmNwidth, &width,
			      XmNheight, &height, NULL);
		set_no_clip(canvas);
		if (positive) {
			XCopyArea(display, window, window, canvas->gc,
				  0, pixels_to_lose, width, height - pixels_to_lose, 0, 0);
			XClearArea(display, window,
				   0, height - pixels_to_lose, width, pixels_to_lose, True);
		} else {
			XCopyArea(display, window, window, canvas->gc,
				  0, 0, width, height - pixels_to_lose, 0, pixels_to_lose);
			XClearArea(display, window, 0, 0, width, pixels_to_lose, True);
		}
	}
}

/*
 * Adjust one XmScrollBar to suit proportions of XmDrawingArea * and the
 * notional canvas. adjust_scrollbar() is as before. adjust_v_scrollbar()
 * uses line units.
 */

void
adjust_scrollbar(sbar, size, visible_size, value)
	Widget          sbar;
	int             size, *value;
	Dimension       visible_size;
{
	/* Assume that minimum is 0 */
	int             slider_size = visible_size;
	int             maximum = size;

	XtVaGetValues(sbar, XmNvalue, value, NULL);
	if (slider_size > maximum)
		slider_size = maximum;
	if (*value > maximum - slider_size)
		*value = maximum - slider_size;
	XtVaSetValues(sbar, XmNvalue, *value,
		      XmNsliderSize, slider_size,
		      XmNmaximum, maximum, NULL);
}

void
adjust_v_scrollbar(sbar, size, visible_size, offset)
	Widget          sbar;
	int             size, *offset;
	Dimension       visible_size;
{
	int             slider_size = (visible_size + 19) / 20;
	int             maximum = (size + 19) / 20;
	int             value;

	XtVaGetValues(sbar, XmNvalue, &value, NULL);
	if (slider_size > maximum)
		slider_size = maximum;
	if (value > maximum - slider_size)
		value = maximum - slider_size;
	XtVaSetValues(sbar, XmNvalue, value,
		      XmNsliderSize, slider_size,
		      XmNmaximum, maximum, NULL);
	*offset = value * 20;
}

/*
 * Set XmScrollBars to suit canvas and XmDrawingArea
 */
void
adjust_size(canvas)
	canvas_p        canvas;
{
	Dimension       width, height;

	XtVaGetValues(canvas->da, XmNwidth, &width,
		      XmNheight, &height, NULL);
	adjust_v_scrollbar(canvas->vsb, canvas->height, height,
			   &canvas->y_offset);
	adjust_scrollbar(canvas->hsb, canvas->width, width,
			 &canvas->x_offset);
}

/*
 * XmDrawingArea resize callback
 */

void
resize(w, client_data, call_data)
	Widget          w;
	XtPointer       client_data;
	XtPointer       call_data;
{
	canvas_p        canvas = (canvas_p) client_data;
	adjust_size(canvas);
}
static char    *da_translations =
"<Btn1Down>: drag_start()\n\
<Btn1Motion>: drag_motion()\n\
<Btn1Up>: drag_stop()";

void            drag_start();
void            drag_motion();
void            drag_stop();
static void     timer();


static XtActionsRec da_actions[] = {
	{"drag_start", drag_start},
	{"drag_motion", drag_motion},
	{"drag_stop", drag_stop}
};

void
register_actions(canvas)
	canvas_p        canvas;
{
	/* Register new actions first, then translations that use them */
	XtAppAddActions(XtWidgetToApplicationContext(canvas->da), da_actions, XtNumber(da_actions));

	XtOverrideTranslations(canvas->da, XtParseTranslationTable(da_translations));

}

static          Boolean
auto_scroll_bar(w, doit, amount)
	Widget          w;
	Boolean         doit;
	int             amount;
{
	int             min, max, value, slider_size, inc, pinc;
	Boolean         space;

	XtVaGetValues(w, XmNminimum, &min,
		      XmNmaximum, &max,
		      XmNvalue, &value,
		      XmNsliderSize, &slider_size,
		      XmNincrement, &inc,
		      XmNpageIncrement, &pinc,
		      NULL);

	value = value + amount;
	space = (value >= min && value + slider_size <= max);