how to get line number of text under mouse.position

[Josh]

Hi

Is it possible to get the line number of the text under the current mouse location; without modifying the caret position.

Ideally without having the synedit as active control,

Am trying to analyze contents of multiple synedit by just moving the mouse over the text, without selecting any.

At the moment am using applicationproperties.onuserinput to intercept mouse movement and detect the control under cursor position.

Code: Pascal  [Select][+][-]

1. var Msg: Cardinal);
2.       cntrl:TControl;
3. begin
4.   if msg<>LM_MOUSEMOVE then exit;
5.   cntrl:= FindLCLControl(mouse.CursorPos);
6.   if cntrl is TSynEdit then
7.   begin
8.      ..
9.    // ctrl under mouse is tsynedit
10.   end                    

[DomingoGP]

Hi,

Maybe this code works for you.

Regards
Domingo.

Code: Pascal  [Select][+][-]

1. uses
2.   lmessages, SynEditTypes;
3.  
4. procedure TForm1.OnUserInputEvent(Sender: TObject; Msg: cardinal);
5. var
6.   cntrl: TControl;
7.   cntrlPos: TPoint;
8.   rowColumn: TPoint;
9. begin
10.   if msg <> LM_MOUSEMOVE then exit;
11.   cntrl := FindLCLControl(mouse.CursorPos);
12.   if cntrl is TSynEdit then
13.   begin
14.     cntrlPos := cntrl.ScreenToControl(mouse.CursorPos);
15.     rowColumn := TSynEdit(cntrl).PixelsToRowColumn(cntrlPos, [scmIncludePartVisible]);
16.     if rowColumn.Y <= TSynEdit(cntrl).Lines.Count then
17.       Label1.Caption := 'Line: ' + IntToStr(rowColumn.Y)
18.     else
19.       Label1.Caption := '';
20.   end
21.   else
22.     label1.Caption := '';
23. end;
24.  

[Josh]

Hi DomingoGP

Thanks that had the info needed. 

First time i've used SynEdit so probably have more questions.

Code: Pascal  [Select][+][-]

1. var Msg: Cardinal);
2.       cntrl:TControl;
3.       LineUnderMouse:AnsiString='';
4. begin
5.   if msg<>LM_MOUSEMOVE then exit;
6.   cntrl:= FindLCLControl(mouse.CursorPos);
7.   if cntrl is TSynEdit then
8.   begin
9.     // ctrl under mouse is tsynedit
10.     LineUnderMouse:=TSynEdit(cntrl).Lines[(tpoint(TSynEdit(cntrl).PixelsToRowColumn(tpoint(cntrl.ScreenToControl(mouse.CursorPos)),[scmIncludePartVisible])).Y)-1]);
11.   end;            

Thanks

[DomingoGP]

You are welcome.

You should check that the line is not greater than TSynEdit(cntrl).lines.count.

For example if the editor has only 2 lines of text and you move the cursor below the second line it will fail when you access TSynEdit(cntrl).lines[3].

[Martin_fr]

From SynEdit

Code: Pascal  [Select][+][-]

1.     // Pixel
2.     function ScreenColumnToXValue(Col: integer): integer;  // map screen column to screen pixel
3.     function ScreenXYToPixels(RowCol: TPhysPoint): TPoint; // converts screen position (1,1) based
4.     function RowColumnToPixels(RowCol: TPoint): TPoint; // deprecated 'use ScreenXYToPixels(TextXYToScreenXY(point))';
5.     function PixelsToRowColumn(Pixels: TPoint; aFlags: TSynCoordinateMappingFlags = [scmLimitToLines]): TPoint;
6.     function PixelsToLogicalPos(const Pixels: TPoint): TPoint;
7.     //
8.     function ScreenRowToRow(ScreenRow: integer; LimitToLines: Boolean = True): integer; override; deprecated 'use ScreenXYToTextXY';
9.     function RowToScreenRow(PhysicalRow: integer): integer; override; deprecated 'use TextXYToScreenXY';
10.     (* ScreenXY:
11.        First visible (scrolled in) screen line is 1
12.        First column is 1 => column does not take scrolling into account
13.     *)
14.     function ScreenXYToTextXY(AScreenXY: TPhysPoint; LimitToLines: Boolean = True): TPhysPoint; override;
15.     function TextXYToScreenXY(APhysTextXY: TPhysPoint): TPhysPoint; override;
16.  

Logical/Physical https://wiki.freepascal.org/SynEdit#Logical.2FPhysical_caret_position

You could use the PixelsTO.... function

PixelsToRowColumn is physical.
PixelsToLogicalPos is the byte in the line text.

[Josh]

Hi

I had to use Y-1 to get the actual line.

I have tested with 2/3 line synedit as well as 0 line and it returns as expected no bang, unless i am missing something.

But i think a safety/sanity check woud be wise..

[Martin_fr]

Hi

I had to use Y-1 to get the actual line.

I have tested with 2/3 line synedit as well as 0 line and it returns as expected no bang, unless i am missing something.

But i think a safety/sanity check woud be wise..

You mean it returns non existing lines? => scmLimitToLines ?

[Josh]

Hi Martin_fr,

when i was testing ideas, i tried a few of those, but they are based on the position of the caret in synedit, unless i done something wrong of course.

it was giving me the line after the one i was after, so i thought it was something to do with one function being non zero based.

did not check too much, but it solved the issue.

[Josh]

Just added test proj that demonstrates

[DomingoGP]

You mean it returns non existing lines? => scmLimitToLines ?

The code I have suggested uses [scmIncludePartVisible] which allows to detect if the cursor is below the last text line if we compare the returned row with lines.count.

I have tested with 2/3 line synedit as well as 0 line and it returns as expected no bang, unless i am missing something.

You are right  Synedit1.Lines[10000] returns an empty string without any error.

[Martin_fr]

when i was testing ideas, i tried a few of those, but they are based on the position of the caret in synedit, unless i done something wrong of course.

None of them should interact with or require the caret.

Pixels => as in mouse, but afaik must be relative to cilentrect.

ScreenXy => text coordinates in the window, but without scrolling => the visible "grid" => top corner is always 1,1

TextXy => (IIRC) physical coordinates in the text.

it was giving me the line after the one i was after, so i thought it was something to do with one function being non zero based.

Those functions are IIRC all 1 based.
The SynEdit.Lines[] property is 0 based.
The carte and SynEdit.LeftChar => 1 based
TopLine... I have to check...

If you look at the sources
- SomeVal: IntIdx; => 0 based (index)
- SomeVal: IntPos; => 1 based (position)
But not everything already has those types.