scrolltext.c

早期freebsd实现

/*
 * A Scrollable Text Output Window
 *
 * David Harrison 
 * University of California,  Berkeley
 * 1986
 *
 * The following is an implementation for a scrollable text output
 * system.  It handles exposure events only (other interactions are
 * under user control).  For scrolling,  a always present scroll bar
 * is implemented.  It detects size changes and compensates accordingly.
 */

#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/X10.h>
#include <sys/types.h>
#include "scrollText.h"

extern char *malloc();
extern char *realloc();
#define alloc(type)		(type *) malloc(sizeof(type))
#define numalloc(type, num)	(type *) malloc((unsigned) (num * sizeof(type)))
#define MAXINT		2147483647

extern XAssocTable *XCreateAssocTable();
extern caddr_t XLookUpAssoc();

static XAssocTable *textWindows = (XAssocTable *) 0;

#define NOOPTION	-1	/* Option hasn't been set yet                */
#define NORMSCROLL	0	/* Smooth scroll on LineToTop and TopToHere  */
#define JUMPSCROLL	1	/* Jump scrolling on LineToTop and TopToHere */

static int ScrollOption = NOOPTION;

typedef char *Generic;

#define DEFAULT_GC textInfo->fontGC[textInfo->curFont]

#define BARSIZE		15
#define BARBORDER	1
#define MAXFONTS	8
#define INITBUFSIZE	1024
#define INITLINES	50
#define INITEXPARY	50
#define XPADDING	2
#define YPADDING	2
#define INTERLINE	5
#define INTERSPACE	1
#define CURSORWIDTH	2
#define EXPANDPERCENT	40
#define BUFSIZE		1024
#define CUROFFSET	1
#define MAXFOREIGN	250
#define NOINDEX		-1

/* The wrap line indicator */
#define WRAPINDSIZE	7
#define STEMOFFSET	5
#define arrow_width 7
#define arrow_height 5
static char arrow_bits[] = {
   0x24, 0x26, 0x3f, 0x06, 0x04};

#define NEWLINE		'\n'
#define BACKSPACE	'\010'
#define NEWFONT		'\006'
#define LOWCHAR		'\040'
#define HIGHCHAR	'\176'

#define CHARMASK	0x00ff	/* Character mask */
#define FONTMASK	0x0700	/* Character font */
#define FONTSHIFT	8	/* Shift amount   */

#define WRAPFLAG	0x01	/* Line wrap flag */

/*
 * Lines are represented by a pointer into the overall array of
 * 16-bit characters.  The lower eight bits is used to indicate the character
 * (in ASCII),  and the next two bits are used to indicate the font
 * the character should be drawn in.
 */

typedef struct txtLine {
    int lineLength;		/* Current line length               */
    int lineHeight;		/* Full height of line in pixels     */
    int lineBaseLine;		/* Current baseline of the line      */
    int lineWidth;		/* Drawing position at end of line   */
    int lineText;		/* Offset into master buffer         */
    int lineFlags;		/* Line wrap flag is here            */
};


/*
 * For ExposeCopy events,  we queue up the redraw requests collapsing
 * them into line redraw requests until the CopyExpose event arrives.
 * The queue is represented as a dynamic array of the following
 * structure:
 */

typedef struct expEvent {
    int lineIndex;		/* Index of line to redraw  */
    int ypos;			/* Drawing position of line */
};


/*
 * The text buffer is represented using a dynamic counted array
 * of 16-bit quantities. This array expands as needed.
 * For the screen representation,  a dynamic counted array
 * of line structures is used.  This array points into the
 * text buffer to denote the start of each line and its parameters.
 * The windows are configured as one overall window which contains
 * the scroll bar as a sub-window along its right edge.  Thus,
 * the text drawing space is actually w-BARSIZE.
 */

#define NOTATBOTTOM	0x01	/* Need to scroll to bottom before appending */
#define FONTNUMWAIT	0x02	/* Waiting for font number                   */
#define COPYEXPOSE	0x04	/* Need to process a copy expose event       */
#define SCREENWRONG	0x08	/* TxtJamStr has invalidated screen contents */

typedef struct txtWin {
    /* Basic text buffer */
    int bufAlloc;		/* Allocated size of buffer           */
    int bufSpot;		/* Current writing position in buffer */
    short *mainBuffer;		/* Main buffer of text                */

    /* Line information */
    int numLines;		/* Number of display lines in buffer */
    int allocLines;		/* Number of lines allocated 	     */
    struct txtLine **txtBuffer;	/* Dynamic array of lines    	     */

    /* Current Window display information */
    Window mainWindow;		/* Text display window       */
    Window scrollBar;		/* Subwindow for scroll bar  */
    Pixmap arrowMap;		/* line wrap indicator       */
    int bgPix, fgPix;		/* Background and cursor     */
    GC CursorGC;		/* gc for the cursor         */
    GC bgGC;			/* gc for erasing things     */
    GC fontGC[MAXFONTS];	/* gc for doing fonts        */
    XFontStruct theFonts[MAXFONTS];/* Display fonts          */
    int  theColors[MAXFONTS];	/* foregrounds of the fonts  */
    int  curFont;		/* current font for tracking */
    int w, h;			/* Current size              */
    int startLine;		/* Top line in display       */
    int endLine;		/* Bottom line in display    */
    int bottomSpace;		/* Space at bottom of screen */
    int flagWord;		/* If non-zero,  not at end  */

    /* For handling ExposeCopy events */
    int exposeSize;		/* Current size of array      */
    int exposeAlloc;		/* Allocated size             */
    struct expEvent **exposeAry;/* Array of line indices      */

    /* Drawing position information */
    int curLine;		/* Current line in buffer    */
    int curX;			/* Current horizontal positi */
    int curY;			/* Current vertical drawing  */
};

/* Flags for the various basic character handling functions */

#define DODISP		0x01	/* Update the display  */
#define NONEWLINE	0x02	/* Dont append newline */



static int InitLine(newLine)
struct txtLine *newLine;	/* Newly created line structure */
/*
 * This routine initializes a newly created line structure.
 */
{
    newLine->lineLength = 0;
    newLine->lineHeight = 0;
    newLine->lineBaseLine = 0;
    newLine->lineWidth = XPADDING;
    newLine->lineText = NOINDEX;
    newLine->lineFlags = 0;
    return 1;
}




int TxtGrab(display, txtWin, program, mainFont, bg, fg, cur)
Display *display;		/* display window is on  */
Window txtWin;			/* Window to take over as scrollable text    */
char *program;			/* Program name for Xdefaults                */
XFontStruct *mainFont;		/* Primary text font                         */
int bg, fg, cur;		/* Background, foreground, and cursor colors */
/*
 * This routine takes control of 'txtWin' and makes it into a scrollable
 * text output window.  It will create a sub-window for the scroll bar
 * with a background of 'bg' and an bar with color 'fg'.  Both fixed width
 * and variable width fonts are supported.  Additional fonts can be loaded
 * using 'TxtAddFont'.  Returns 0 if there were problems,  non-zero if
 * everything went ok.
 */
{
    struct txtWin *newWin;	/* Text package specific information */
    XWindowAttributes winInfo;	/* Window information                */
    int index;
    XGCValues gc_val;
    
    if (textWindows == (XAssocTable *) 0) {
	textWindows = XCreateAssocTable(32);
	if (textWindows == (XAssocTable *) 0) return(0);
    }
    if (XGetWindowAttributes(display, txtWin, &winInfo) == 0) return 0;

    if (ScrollOption == NOOPTION) {
	/* Read to see if the user wants jump scrolling or not */
	if (XGetDefault(display, program, "JumpScroll")) {
	    ScrollOption = JUMPSCROLL;
	} else {
	    ScrollOption = NORMSCROLL;
	}
    }

    /* Initialize local structure */
    newWin = alloc(struct txtWin);

    /* Initialize arrow pixmap */
    newWin->arrowMap = XCreatePixmapFromBitmapData(display, txtWin,
						   arrow_bits,
						   arrow_width, arrow_height,
						   cur, bg,
						   DisplayPlanes(display, 0));

    newWin->bufAlloc = INITBUFSIZE;
    newWin->bufSpot = 0;
    newWin->mainBuffer = numalloc(short, INITBUFSIZE);

    newWin->numLines = 1;
    newWin->allocLines = INITLINES;
    newWin->txtBuffer = numalloc(struct txtLine *, INITLINES);
    for (index = 0;  index < INITLINES;  index++) {
	newWin->txtBuffer[index] = alloc(struct txtLine);
	InitLine(newWin->txtBuffer[index]);
    }

    /* Window display information */
    newWin->mainWindow = txtWin;
    newWin->w = winInfo.width;
    newWin->h = winInfo.height;
    newWin->startLine = 0;
    newWin->endLine = 0;
    newWin->bottomSpace = winInfo.height
      - YPADDING - mainFont->ascent - mainFont->descent - INTERLINE;
    newWin->flagWord = 0;
    newWin->bgPix = bg;
    newWin->fgPix = fg;

    /* Scroll Bar Creation */
    newWin->scrollBar = XCreateSimpleWindow(display, txtWin,
				      winInfo.width - BARSIZE,
				      0, BARSIZE - (2*BARBORDER),
				      winInfo.height - (2*BARBORDER),
				      BARBORDER, 
				      fg, bg);
    XSelectInput(display, newWin->scrollBar, ExposureMask|ButtonReleaseMask);
    XMapRaised(display, newWin->scrollBar);

    /* Font and Color Initialization */
    newWin->theFonts[0] = *mainFont;
    newWin->theColors[0] = fg;
    gc_val.function = GXcopy;
    gc_val.plane_mask = AllPlanes;
    gc_val.foreground = fg;
    gc_val.background = bg;
    gc_val.graphics_exposures = 1;
    gc_val.font = mainFont->fid;
    gc_val.line_width = 1;
    gc_val.line_style = LineSolid;

    newWin->fontGC[0] = XCreateGC(display, txtWin,
				  GCFunction | GCPlaneMask |
				  GCForeground | GCBackground |
				  GCGraphicsExposures | GCFont,
				  &gc_val);

    gc_val.foreground = cur;
    newWin->CursorGC = XCreateGC(display, txtWin,
				 GCFunction | GCPlaneMask |
				  GCForeground | GCBackground |
				  GCLineStyle | GCLineWidth,
				  &gc_val);

    gc_val.foreground = bg;
    newWin->bgGC = XCreateGC(display, txtWin,
				  GCFunction | GCPlaneMask |
				  GCForeground | GCBackground |
				  GCGraphicsExposures | GCFont,
				  &gc_val);


    for (index = 1;  index < MAXFONTS;  index++) {
	newWin->theFonts[index].fid = 0;
	newWin->fontGC[index] = 0;
    }

    
    /* Initialize size of first line */
    newWin->txtBuffer[0]->lineHeight = newWin->theFonts[0].ascent +
	newWin->theFonts[0].descent;
    newWin->txtBuffer[0]->lineText = 0;

    /* ExposeCopy array initialization */
    newWin->exposeSize = 0;
    newWin->exposeAlloc = INITEXPARY;
    newWin->exposeAry = numalloc(struct expEvent *, INITEXPARY);
    for (index = 0;  index < newWin->exposeAlloc;  index++)
      newWin->exposeAry[index] = alloc(struct expEvent);
    /* Put plus infinity in last slot for sorting purposes */
    newWin->exposeAry[0]->lineIndex = MAXINT;

    /* Drawing Position Information */
    newWin->curLine = 0;
    newWin->curX = 0;
    newWin->curY = YPADDING + mainFont->ascent + mainFont->descent;

    /* Attach it to both windows */
    XMakeAssoc(display, textWindows, (XID) txtWin, (caddr_t) newWin);
    XMakeAssoc(display, textWindows, (XID) newWin->scrollBar, (caddr_t) newWin);
    return 1;
}


int TxtRelease(display, w)
Display *display;
Window w;			/* Window to release */
/*
 * This routine releases all resources associated with the
 * specified window which are consumed by the text
 * window package. This includes the entire text buffer,  line start
 * array,  and the scroll bar window.  However,  the window
 * itself is NOT destroyed.  The routine will return zero if
 * the window is not owned by the text window package.
 */
{
    struct txtWin *textInfo;
    int index;

    if ((textInfo = (struct txtWin *) XLookUpAssoc(display,
						 textWindows, (XID) w)) == 0)
      return 0;

    for (index = 0; index < MAXFONTS; index++)
	if (textInfo->fontGC[index] != 0)
	    XFreeGC(display, textInfo->fontGC[index]);

    free((Generic) textInfo->mainBuffer);
    for (index = 0;  index < textInfo->numLines;  index++) {
	free((Generic) textInfo->txtBuffer[index]);
    }
    free((Generic) textInfo->txtBuffer);
    XDestroyWindow(display, textInfo->scrollBar);
    for (index = 0;  index < textInfo->exposeSize;  index++) {
	free((Generic) textInfo->exposeAry[index]);
    }
    free((Generic) textInfo->exposeAry);
    XDeleteAssoc(display, textWindows, (XID) w);
    free((Generic) textInfo);
    return 1;
}



static int RecompBuffer(textInfo)
struct txtWin *textInfo;	/* Text window information */
/*
 * This routine recomputes all line breaks in a buffer after
 * a change in window size or font.  This is done by throwing
 * away the old line start array and recomputing it.  Although
 * a lot of this work is also done elsewhere,  it has been included
 * inline here for efficiency.
 */
{
    int startPos, endSize, linenum;
    register int index, chsize, curfont;
    register short *bufptr;
    register XFontStruct *fontptr;
    register struct txtLine *lineptr;
    char theChar;

    /* Record the old position so we can come back to it */
    for (startPos = textInfo->txtBuffer[textInfo->startLine]->lineText;
	 (startPos > 0) && (textInfo->mainBuffer[startPos] != '\n');
	 startPos--)
      /* null loop body */;
    
    /* Clear out the old line start array */
    for (index = 0;  index < textInfo->numLines;  index++) {
	InitLine(textInfo->txtBuffer[index]);
    }

    /* Initialize first line */
    textInfo->txtBuffer[0]->lineHeight =
	textInfo->theFonts[0].ascent + textInfo->theFonts[0].descent;
    textInfo->txtBuffer[0]->lineText = 0;

    /* Process the text back into lines */
    endSize = textInfo->w - BARSIZE - WRAPINDSIZE;
    bufptr = textInfo->mainBuffer;
    lineptr = textInfo->txtBuffer[0];
    linenum = 0;
    fontptr = &(textInfo->theFonts[0]);
    curfont = 0;
    for (index = 0;  index < textInfo->bufSpot;  index++) {
	theChar = bufptr[index] & CHARMASK;
	
	if ((bufptr[index] & FONTMASK) != curfont) {
	    int newFontNum, heightDiff;

	    /* Switch fonts */
	    newFontNum = (bufptr[index] & FONTMASK) >> FONTSHIFT;
	    if (textInfo->theFonts[newFontNum].fid != 0) {
		/* Valid font */
		curfont = bufptr[index] & FONTMASK;
		fontptr = &(textInfo->theFonts[newFontNum]);
		heightDiff = (fontptr->ascent + fontptr->descent) -
		    lineptr->lineHeight;
		if (heightDiff < 0) heightDiff = 0;
		lineptr->lineHeight += heightDiff;
	    }
	}
	if (theChar == '\n') {
	    /* Handle new line */
	    if (linenum >= textInfo->allocLines-1)
	      /* Expand number of lines */
	      ExpandLines(textInfo);
	    linenum++;
	    lineptr = textInfo->txtBuffer[linenum];
	    /* Initialize next line */
	    lineptr->lineHeight = fontptr->ascent + fontptr->descent;
	    lineptr->lineText = index+1;
	    /* Check to see if its the starting line */
	    if (index == startPos) textInfo->startLine = linenum;
	} else {
	    /* Handle normal character */
	    chsize = CharSize(textInfo, linenum, index);
	    if (lineptr->lineWidth + chsize > endSize) {
		/* Handle line wrap */
		lineptr->lineFlags |= WRAPFLAG;
		if (linenum >= textInfo->allocLines-1)
		  /* Expand number of lines */
		  ExpandLines(textInfo);
		linenum++;
		lineptr = textInfo->txtBuffer[linenum];
		/* Initialize next line */
		lineptr->lineHeight = fontptr->ascent + fontptr->descent;
		lineptr->lineText = index;
		lineptr->lineLength = 1;
		lineptr->lineWidth += chsize;
	    } else {
		/* Handle normal addition of character */
		lineptr->lineLength += 1;
		lineptr->lineWidth += chsize;
	    }
	}
    }
    /* We now have a valid line array.  Let's clean up some other fields. */