TRichView.com

Posted: **Sun Dec 12, 2021 6:12 pm**

Hi Sergey,

When working with a regular rve I've noticed if I have empty lines selected there is no visual feedback to tell you that. So, here are 2 examples of how it works normally:

: Middle lines are actually selected; Image1.png (3.18 KiB) Viewed 4246 times

: All lines selected, middle lines don't show selection; Image3.png (3.46 KiB) Viewed 4246 times

What I'm used to is this with the same 2 examples showing all the selection areas:

: Middle lines are selected; selection shown; Image2.png (3.21 KiB) Viewed 4246 times

: All lines selected, middle lines DO show selection; Image4.png (3.56 KiB) Viewed 4246 times

I put some code in my rve's paint method (see below) and have it working. Maybe it will help others wanting to do the same thing.

However...

My questions are:

- Is there already a built-in way of doing this that I've missed? Some option or property?
If not, then
- Does the code I wrote (below) seem reasonable?
- Note that I draw the "pilcrow" symbol (¶) "manually" since my paint code "overwrites" the built-in ¶ in empty lines.

: Image showing special chars visible; Image5.png (4.39 KiB) Viewed 4246 times

- Can you tell me where in the source you are drawing that ¶ symbol when rvscParagraph is in RVVisibleSpecialCharacters and they are being shown? I'm not sure what I've done will work in all circumstances and I think I'd be better off replicating whatever it is you're doing.

Thanks Sergey

Code: Select all

procedure TForm1.rvePaint(Sender: TCustomRichView; ACanvas: TCanvas;
  Prepaint: Boolean);
var
  i, YOffSet: integer;
  FStart, FSOff, FEnd, FEoff: integer;
  DItemStart, DOffStart, DItemEnd, DOffEnd: integer;
  DItem: TRVDrawLineInfo;
  r: TRect;
begin

  if Sender.ItemCount = 0 then exit;

  try

    //Selection Area Marker (vertical line in rve left margin at empty lines)
    if ShowSelMarker1.Checked and Sender.SelectionExists then 
    begin

      //Get current selection:
      Sender.GetSelectionBounds(FStart, FSOff, FEnd, FEoff, true);

      //Convert start/end items to DrawItems:
      Sender.RVData.Item2DrawItem(FStart,FSOff,DItemStart,DOffStart);
      Sender.RVData.Item2DrawItem(Fend,FEoff,DItemEnd,DOffEnd);

      //Draw selection color on any empty DrawItem lines
      for i := DItemStart to DItemEnd do
      begin

        DItem := Sender.RVData.DrawItems[i];
        r.Left := Sender.LeftMargin - 1;
        r.Right := r.Left + 6;

        YOffSet := ( Sender.VScrollPos * Sender.VSmallStep );
        r.Top := DItem.Top - YOffSet;
        r.Bottom := DITem.Top + DItem.Height  - YOffSet;

        ACanvas.Brush.Color := Sender.Style.SelColor;

        //DrawItem is empty:
        if (DItem.TextLength = 0) and //not an image:
           (Sender.GetItemStyle(DItem.ItemNo) = rvsNormal ) then
        begin
          ACanvas.FillRect(r);
          if (rvoShowSpecialCharacters in Sender.Options) and
             (rvscParagraph in RVVisibleSpecialCharacters) then
          begin

            ACanvas.Font.Size :=
              Sender.Style.TextStyles[Sender.GetItemStyle(DItem.ItemNo)].Size;
            ACanvas.Font.Name :=
              Sender.Style.TextStyles[Sender.GetItemStyle(DItem.ItemNo)].FontName;
            ACanvas.Font.Charset := DEFAULT_CHARSET;
            ACanvas.Font.Color := Sender.Style.SpecialCharactersColor;

            r.Right := r.Left + ACanvas.TextWidth(chr(182)); //chr(182) = '¶'
            ACanvas.FillRect(r);

            ACanvas.Brush.Style := bsClear;
            ACanvas.TextOut(r.Left,r.Top,chr(182));

          end;

        end;

      end;

    end;
...

Posted: **Mon Dec 13, 2021 4:29 pm**

There are no standard way to display empty selected lines.
Pilcrow symbols are drawn in DrawParaMark procedure (which is inside TCustomRVFormattedData.PaintTo, in CRVFData.pas).

If the code works, I believe it's ok.
Sender.GetItemStyle(DItem.ItemNo) = rvsNormal
can be changed to
Sender.GetItemStyle(DItem.ItemNo) >= 0
to support all text items.

Posted: **Mon Dec 13, 2021 8:28 pm**

Hi Sergey,

Thanks for the info. I looked at DrawParaMark and, as I suspected, there is a lot more going on in there than I'd want to try and replicate.

So, if I have special chars showing, I move my selection drawing into the left margin so I don't "stomp" on the special chars. When special chars are off (which is most of the time), I show the selection starting at the left margin 5px wide as before. Since I'm only interested in marking the empty lines, while not ideal, this will work. I want to keep it fairly simple to maintain!

: Image21.png (6.56 KiB) Viewed 4114 times

: Image22.png (5.64 KiB) Viewed 4114 times

Thanks again

Stan

Code: Select all

      //Get current selection:
      Sender.GetSelectionBounds(FStart, FSOff, FEnd, FEoff, true);

      //Convert start/end items to DrawItems:
      Sender.RVData.Item2DrawItem(FStart,FSOff,DItemStart,DOffStart);
      Sender.RVData.Item2DrawItem(Fend,FEoff,DItemEnd,DOffEnd);

      //Draw selection color on any empty DrawItem lines
      for i := DItemStart to DItemEnd do
      begin

        DItem := Sender.RVData.DrawItems[i];
        r.Left := Sender.LeftMargin - 1;
        r.Right := r.Left + 6;

        if (rvoShowSpecialCharacters in Sender.Options) and
           (rvscParagraph in RVVisibleSpecialCharacters) then
        begin
          r.Left := 0;
          r.Right := r.Left + Sender.LeftMargin - 1;
        end;

        YOffSet := ( Sender.VScrollPos * Sender.VSmallStep );
        r.Top := DItem.Top - YOffSet;
        r.Bottom := DITem.Top + DItem.Height  - YOffSet;

        ACanvas.Brush.Color := Sender.Style.SelColor;

        //DrawItem is empty:
        if (DItem.TextLength = 0) and //not an image:
           (Sender.GetItemStyle(DItem.ItemNo) >= 0 ) then
          ACanvas.FillRect(r);
         ...

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