kwrite widget- better performance

[Dave Robbins]

Hi

I tried this and it works great.
I view kdevelop via a remote x-server and before scrolling was very jagged.
Now everthing is smooth.

Thanks
Dave

Vladimir Dvorak wrote:

>  Hi all,
> I have used a modified text-drawing function in kwrite widget
> for some time. It looks much better especially on remote X-server.
> Let's try to change ./kdevelop/kwrite/kwdoc.cpp :
>
> ////////////////////////////////////////////////////////////////////////
> void
> KWriteDoc::paintTextLine(QPainter &paint, int line, int xStart, int xEnd)
> {
>   int y;
>   TextLine *textLine;
>   int z, x;
>   char ch;
>   Attribute *a = 0L;
>   int attr, nextAttr;
>   int xs;
>   int xc, zc;
>   static char aLB[256];
>   int aCnt, xcp;
>
>   y = 0;//line*fontHeight - yPos;
>   if (line >= (int) contents.count()) {
>     paint.fillRect(0,y,xEnd - xStart,fontHeight,colors[4]);
>     return;
>   }
> //printf("xStart = %d, xEnd = %d, line = %d\n",xStart,xEnd,line);
> //printf("text = ");
>   textLine = contents.at(line);
>
>   z = 0;
>   x = 0;
>   do {
>     xc = x;
>     ch = textLine->getChar(z);
>     if (ch == '\t') {
>       x += tabWidth - (x % tabWidth);
>     } else {
>       a = &attribs[textLine->getAttr(z)];
>       x += a->fm.width(&ch,1);
>     }
>     z++;
>   } while (x <= xStart);
>   zc = z - 1;
>
>   xs = xStart;
>   attr = textLine->getRawAttr(zc);
>   while (x < xEnd) {
>     nextAttr = textLine->getRawAttr(z);
>     if ((nextAttr ^ attr) & (taSelectMask | 256)) {
>       paint.fillRect(xs - xStart,y,x - xs,fontHeight,colors[attr >> taShift]);
>       xs = x;
>       attr = nextAttr;
>     }
>     ch = textLine->getChar(z);
>     if (ch == '\t') {
>       x += tabWidth - (x % tabWidth);
>     } else {
>       a = &attribs[attr & taAttrMask];
>       x += a->fm.width(&ch,1);
>     }
>     z++;
>   }
>
>   paint.fillRect(xs - xStart,y,xEnd - xs,fontHeight,colors[attr >> taShift]);
>
>   y += fontAscent -1;
>   attr = -1;
>   aCnt = 0;
>   xcp  = xc;
>
>   while (xc < xEnd) {
>     ch = textLine->getChar(zc);
>
>     if (ch == '\t') {
>       xc += tabWidth - (xc % tabWidth);
>       if(aCnt!=0) {
>         paint.drawText(xcp - xStart,y,aLB,aCnt);
>         aCnt = 0;
>       }
>       xcp  = xc;
>     }
>
>     else {
>       nextAttr = textLine->getRawAttr(zc);
>       if (nextAttr != attr) {
>
>         if(aCnt!=0) {
>           paint.drawText(xcp - xStart,y,aLB,aCnt);
>           aCnt = 0;
>           xcp  = xc;
>         }
>
>         attr = nextAttr;
>         a = &attribs[attr & taAttrMask];
>         if (attr & taSelectMask) paint.setPen(a->selCol); else paint.setPen(a->col);
>         paint.setFont(a->font);
>       }
>
>       aLB[aCnt++] = ch;
>       xc += a->fm.width(&ch,1);
>
>       if(aCnt == 256) {
>         paint.drawText(xcp - xStart,y,aLB,aCnt);
>         aCnt = 0;
>         xcp  = xc;
>       }
>
>     }
>     zc++;
>   }
>
>   if(aCnt!=0) {
>     paint.drawText(xcp - xStart,y,aLB,aCnt);
>     aCnt = 0;
>     xcp  = xc;
>   }
> //printf("\n");
> }
>
> //////////////////////////////////////////////////////////////////////////