tktextdisp.c

linux系统下的音频通信

/* 
 * tkTextDisp.c --
 *
 *	This module provides facilities to display text widgets.  It is
 *	the only place where information is kept about the screen layout
 *	of text widgets.
 *
 * Copyright (c) 1992-1994 The Regents of the University of California.
 * Copyright (c) 1994-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * SCCS: @(#) tkTextDisp.c 1.124 97/07/11 18:01:03
 */

#include "tkPort.h"
#include "tkInt.h"
#include "tkText.h"

/*
 * The following structure describes how to display a range of characters.
 * The information is generated by scanning all of the tags associated
 * with the characters and combining that with default information for
 * the overall widget.  These structures form the hash keys for
 * dInfoPtr->styleTable.
 */

typedef struct StyleValues {
    Tk_3DBorder border;		/* Used for drawing background under text.
				 * NULL means use widget background. */
    int borderWidth;		/* Width of 3-D border for background. */
    int relief;			/* 3-D relief for background. */
    Pixmap bgStipple;		/* Stipple bitmap for background.  None
				 * means draw solid. */
    XColor *fgColor;		/* Foreground color for text. */
    Tk_Font tkfont;		/* Font for displaying text. */
    Pixmap fgStipple;		/* Stipple bitmap for text and other
				 * foreground stuff.   None means draw
				 * solid.*/
    int justify;		/* Justification style for text. */
    int lMargin1;		/* Left margin, in pixels, for first display
				 * line of each text line. */
    int lMargin2;		/* Left margin, in pixels, for second and
				 * later display lines of each text line. */
    int offset;			/* Offset in pixels of baseline, relative to
				 * baseline of line. */
    int overstrike;		/* Non-zero means draw overstrike through
				 * text. */
    int rMargin;		/* Right margin, in pixels. */
    int spacing1;		/* Spacing above first dline in text line. */
    int spacing2;		/* Spacing between lines of dline. */
    int spacing3;		/* Spacing below last dline in text line. */
    TkTextTabArray *tabArrayPtr;/* Locations and types of tab stops (may
				 * be NULL). */
    int underline;		/* Non-zero means draw underline underneath
				 * text. */
    Tk_Uid wrapMode;		/* How to handle wrap-around for this tag.
				 * One of tkTextCharUid, tkTextNoneUid,
				 * or tkTextWordUid. */
} StyleValues;

/*
 * The following structure extends the StyleValues structure above with
 * graphics contexts used to actually draw the characters.  The entries
 * in dInfoPtr->styleTable point to structures of this type.
 */

typedef struct TextStyle {
    int refCount;		/* Number of times this structure is
				 * referenced in Chunks. */
    GC bgGC;			/* Graphics context for background.  None
				 * means use widget background. */
    GC fgGC;			/* Graphics context for foreground. */
    StyleValues *sValuePtr;	/* Raw information from which GCs were
				 * derived. */
    Tcl_HashEntry *hPtr;	/* Pointer to entry in styleTable.  Used
				 * to delete entry. */
} TextStyle;

/*
 * The following macro determines whether two styles have the same
 * background so that, for example, no beveled border should be drawn
 * between them.
 */

#define SAME_BACKGROUND(s1, s2) \
    (((s1)->sValuePtr->border == (s2)->sValuePtr->border) \
        && ((s1)->sValuePtr->borderWidth == (s2)->sValuePtr->borderWidth) \
        && ((s1)->sValuePtr->relief == (s2)->sValuePtr->relief) \
        && ((s1)->sValuePtr->bgStipple == (s2)->sValuePtr->bgStipple))

/*
 * The following structure describes one line of the display, which may
 * be either part or all of one line of the text.
 */

typedef struct DLine {
    TkTextIndex index;		/* Identifies first character in text
				 * that is displayed on this line. */
    int count;			/* Number of characters accounted for by this
				 * display line, including a trailing space
				 * or newline that isn't actually displayed. */
    int y;			/* Y-position at which line is supposed to
				 * be drawn (topmost pixel of rectangular
				 * area occupied by line). */
    int oldY;			/* Y-position at which line currently
				 * appears on display.  -1 means line isn't
				 * currently visible on display and must be
				 * redrawn.  This is used to move lines by
				 * scrolling rather than re-drawing. */
    int height;			/* Height of line, in pixels. */
    int baseline;		/* Offset of text baseline from y, in
				 * pixels. */
    int spaceAbove;		/* How much extra space was added to the
				 * top of the line because of spacing
				 * options.  This is included in height
				 * and baseline. */
    int spaceBelow;		/* How much extra space was added to the
				 * bottom of the line because of spacing
				 * options.  This is included in height. */
    int length;			/* Total length of line, in pixels. */
    TkTextDispChunk *chunkPtr;	/* Pointer to first chunk in list of all
				 * of those that are displayed on this
				 * line of the screen. */
    struct DLine *nextPtr;	/* Next in list of all display lines for
				 * this window.   The list is sorted in
				 * order from top to bottom.  Note:  the
				 * next DLine doesn't always correspond
				 * to the next line of text:  (a) can have
				 * multiple DLines for one text line, and
				 * (b) can have gaps where DLine's have been
				 * deleted because they're out of date. */
    int flags;			/* Various flag bits:  see below for values. */
} DLine;

/*
 * Flag bits for DLine structures:
 *
 * HAS_3D_BORDER -		Non-zero means that at least one of the
 *				chunks in this line has a 3D border, so
 *				it potentially interacts with 3D borders
 *				in neighboring lines (see
 *				DisplayLineBackground).
 * NEW_LAYOUT -			Non-zero means that the line has been
 *				re-layed out since the last time the
 *				display was updated.
 * TOP_LINE -			Non-zero means that this was the top line
 *				in the window the last time that the window
 *				was laid out.  This is important because
 *				a line may be displayed differently if its
 *				at the top or bottom than if it's in the
 *				middle (e.g. beveled edges aren't displayed
 *				for middle lines if the adjacent line has
 *				a similar background).
 * BOTTOM_LINE -		Non-zero means that this was the bottom line
 *				in the window the last time that the window
 *				was laid out.
 */

#define HAS_3D_BORDER	1
#define NEW_LAYOUT	2
#define TOP_LINE	4
#define BOTTOM_LINE	8

/*
 * Overall display information for a text widget:
 */

typedef struct TextDInfo {
    Tcl_HashTable styleTable;	/* Hash table that maps from StyleValues
				 * to TextStyles for this widget. */
    DLine *dLinePtr;		/* First in list of all display lines for
				 * this widget, in order from top to bottom. */
    GC copyGC;			/* Graphics context for copying from off-
				 * screen pixmaps onto screen. */
    GC scrollGC;		/* Graphics context for copying from one place
				 * in the window to another (scrolling):
				 * differs from copyGC in that we need to get
				 * GraphicsExpose events. */
    int x;			/* First x-coordinate that may be used for
				 * actually displaying line information.
				 * Leaves space for border, etc. */
    int y;			/* First y-coordinate that may be used for
				 * actually displaying line information.
				 * Leaves space for border, etc. */
    int maxX;			/* First x-coordinate to right of available
				 * space for displaying lines. */
    int maxY;			/* First y-coordinate below available
				 * space for displaying lines. */
    int topOfEof;		/* Top-most pixel (lowest y-value) that has
				 * been drawn in the appropriate fashion for
				 * the portion of the window after the last
				 * line of the text.  This field is used to
				 * figure out when to redraw part or all of
				 * the eof field. */

    /*
     * Information used for scrolling:
     */

    int newCharOffset;		/* Desired x scroll position, measured as the
				 * number of average-size characters off-screen
				 * to the left for a line with no left
				 * margin. */
    int curPixelOffset;		/* Actual x scroll position, measured as the
				 * number of pixels off-screen to the left. */
    int maxLength;		/* Length in pixels of longest line that's
				 * visible in window (length may exceed window
				 * size).  If there's no wrapping, this will
				 * be zero. */
    double xScrollFirst, xScrollLast;
				/* Most recent values reported to horizontal
				 * scrollbar;  used to eliminate unnecessary
				 * reports. */
    double yScrollFirst, yScrollLast;
				/* Most recent values reported to vertical
				 * scrollbar;  used to eliminate unnecessary
				 * reports. */

    /*
     * The following information is used to implement scanning:
     */

    int scanMarkChar;		/* Character that was at the left edge of
				 * the window when the scan started. */
    int scanMarkX;		/* X-position of mouse at time scan started. */
    int scanTotalScroll;	/* Total scrolling (in screen lines) that has
				 * occurred since scanMarkY was set. */
    int scanMarkY;		/* Y-position of mouse at time scan started. */

    /*
     * Miscellaneous information:
     */

    int dLinesInvalidated;	/* This value is set to 1 whenever something
				 * happens that invalidates information in
				 * DLine structures;  if a redisplay
				 * is in progress, it will see this and
				 * abort the redisplay.  This is needed
				 * because, for example, an embedded window
				 * could change its size when it is first
				 * displayed, invalidating the DLine that
				 * is currently being displayed.  If redisplay
				 * continues, it will use freed memory and
				 * could dump core. */
    int flags;			/* Various flag values:  see below for
				 * definitions. */
} TextDInfo;

/*
 * In TkTextDispChunk structures for character segments, the clientData
 * field points to one of the following structures:
 */

typedef struct CharInfo {
    int numChars;		/* Number of characters to display. */
    char chars[4];		/* Characters to display.  Actual size
				 * will be numChars, not 4.  THIS MUST BE
				 * THE LAST FIELD IN THE STRUCTURE. */
} CharInfo;

/*
 * Flag values for TextDInfo structures:
 *
 * DINFO_OUT_OF_DATE:		Non-zero means that the DLine structures
 *				for this window are partially or completely
 *				out of date and need to be recomputed.
 * REDRAW_PENDING:		Means that a when-idle handler has been
 *				scheduled to update the display.
 * REDRAW_BORDERS:		Means window border or pad area has
 *				potentially been damaged and must be redrawn.
 * REPICK_NEEDED:		1 means that the widget has been modified
 *				in a way that could change the current
 *				character (a different character might be
 *				under the mouse cursor now).  Need to
 *				recompute the current character before
 *				the next redisplay.
 */

#define DINFO_OUT_OF_DATE	1
#define REDRAW_PENDING		2
#define REDRAW_BORDERS		4
#define REPICK_NEEDED		8

/*
 * The following counters keep statistics about redisplay that can be
 * checked to see how clever this code is at reducing redisplays.
 */

static int numRedisplays;	/* Number of calls to DisplayText. */
static int linesRedrawn;	/* Number of calls to DisplayDLine. */
static int numCopies;		/* Number of calls to XCopyArea to copy part
				 * of the screen. */

/*
 * Forward declarations for procedures defined later in this file:
 */

static void		AdjustForTab _ANSI_ARGS_((TkText *textPtr,
			    TkTextTabArray *tabArrayPtr, int index,
			    TkTextDispChunk *chunkPtr));
static void		CharBboxProc _ANSI_ARGS_((TkTextDispChunk *chunkPtr,
			    int index, int y, int lineHeight, int baseline,
			    int *xPtr, int *yPtr, int *widthPtr,
			    int *heightPtr));
static void		CharDisplayProc _ANSI_ARGS_((TkTextDispChunk *chunkPtr,
			    int x, int y, int height, int baseline,
			    Display *display, Drawable dst, int screenY));
static int		CharMeasureProc _ANSI_ARGS_((TkTextDispChunk *chunkPtr,
			    int x));
static void		CharUndisplayProc _ANSI_ARGS_((TkText *textPtr,
			    TkTextDispChunk *chunkPtr));
static void		DisplayDLine _ANSI_ARGS_((TkText *textPtr,
			    DLine *dlPtr, DLine *prevPtr, Pixmap pixmap));
static void		DisplayLineBackground _ANSI_ARGS_((TkText *textPtr,
			    DLine *dlPtr, DLine *prevPtr, Pixmap pixmap));
static void		DisplayText _ANSI_ARGS_((ClientData clientData));
static DLine *		FindDLine _ANSI_ARGS_((DLine *dlPtr,
			    TkTextIndex *indexPtr));
static void		FreeDLines _ANSI_ARGS_((TkText *textPtr,
			    DLine *firstPtr, DLine *lastPtr, int unlink));
static void		FreeStyle _ANSI_ARGS_((TkText *textPtr,
			    TextStyle *stylePtr));
static TextStyle *	GetStyle _ANSI_ARGS_((TkText *textPtr,
			    TkTextIndex *indexPtr));
static void		GetXView _ANSI_ARGS_((Tcl_Interp *interp,
			    TkText *textPtr, int report));
static void		GetYView _ANSI_ARGS_((Tcl_Interp *interp,
			    TkText *textPtr, int report));
static DLine *		LayoutDLine _ANSI_ARGS_((TkText *textPtr,
			    TkTextIndex *indexPtr));
static int		MeasureChars _ANSI_ARGS_((Tk_Font tkfont,
			    CONST char *source, int maxChars, int startX,
			    int maxX, int tabOrigin, int *nextXPtr));
static void		MeasureUp _ANSI_ARGS_((TkText *textPtr,
			    TkTextIndex *srcPtr, int distance,
			    TkTextIndex *dstPtr));
static int		NextTabStop _ANSI_ARGS_((Tk_Font tkfont, int x,
			    int tabOrigin));
static void		UpdateDisplayInfo _ANSI_ARGS_((TkText *textPtr));
static void		ScrollByLines _ANSI_ARGS_((TkText *textPtr,
			    int offset));
static int		SizeOfTab _ANSI_ARGS_((TkText *textPtr,
			    TkTextTabArray *tabArrayPtr, int index, int x,
			    int maxX));
static void		TextInvalidateRegion _ANSI_ARGS_((TkText *textPtr,
			    TkRegion region));


/*
 *----------------------------------------------------------------------
 *
 * TkTextCreateDInfo --
 *
 *	This procedure is called when a new text widget is created.
 *	Its job is to set up display-related information for the widget.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	A TextDInfo data structure is allocated and initialized and attached
 *	to textPtr.
 *
 *----------------------------------------------------------------------
 */

void
TkTextCreateDInfo(textPtr)
    TkText *textPtr;		/* Overall information for text widget. */
{
    register TextDInfo *dInfoPtr;
    XGCValues gcValues;

    dInfoPtr = (TextDInfo *) ckalloc(sizeof(TextDInfo));
    Tcl_InitHashTable(&dInfoPtr->styleTable, sizeof(StyleValues)/sizeof(int));
    dInfoPtr->dLinePtr = NULL;
    dInfoPtr->copyGC = None;
    gcValues.graphics_exposures = True;
    dInfoPtr->scrollGC = Tk_GetGC(textPtr->tkwin, GCGraphicsExposures,
	    &gcValues);
    dInfoPtr->topOfEof = 0;
    dInfoPtr->newCharOffset = 0;
    dInfoPtr->curPixelOffset = 0;
    dInfoPtr->maxLength = 0;
    dInfoPtr->xScrollFirst = -1;
    dInfoPtr->xScrollLast = -1;
    dInfoPtr->yScrollFirst = -1;
    dInfoPtr->yScrollLast = -1;
    dInfoPtr->scanMarkChar = 0;
    dInfoPtr->scanMarkX = 0;
    dInfoPtr->scanTotalScroll = 0;
    dInfoPtr->scanMarkY = 0;
    dInfoPtr->dLinesInvalidated = 0;
    dInfoPtr->flags = DINFO_OUT_OF_DATE;
    textPtr->dInfoPtr = dInfoPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * TkTextFreeDInfo --
 *