Inserting, Saving and Loading Images

[skalogryz]

Please note that stretch drawing might not always be the desired result.
So, it's up to you how to draw the inserted inline object, you'll always have the size of the rectangle area where the object needs to be drawn at. (No pixels would be drawn outside of the area)

[rick2691]

Thanks, but I am not sure why I would not want to resize something. That said, I am going to build a function to resize proportionately, which is what I always need.

Rick.

[rick2691]

Unfortunately it isn't over, an inserted image won't save to disk.

Rick

[skalogryz]

Unfortunately it isn't over, an inserted image won't save to disk.

Yeah, I know. You mentioned it several times before
Working on it.

[rick2691]

Sorry for the nag... I had only thought that once it had a grip frame it meant that it was built by a callback, and could be saved.

Rick

[skalogryz]

Sorry for the nag... I had only thought that once it had a grip frame it meant that it was built by a callback, and could be saved.

Not that easy. Windows needs to recognize the image ... as an image... in order to be able to save it to rtf.

[rick2691]

I came across this code that is supposed to work for RxRichEdit. I has function calls that are specific to that driver, so it hard for me to sort out what is actually needed. I also think that it defective code... incomplete call formats that omit parameters. But maybe you might can get something out of it.

Code: Pascal  [Select][+][-]

1. // Insert a image into a TRxRichEdit?
2. // Author: Thomas Stutz
3.  
4.  
5. uses
6.   RichEdit;
7.  
8. // Stream Callback function
9. type
10.   TEditStreamCallBack = function(dwCookie: Longint; pbBuff: PByte;
11.     cb: Longint; var pcb: Longint): DWORD;
12.   stdcall;
13.  
14.   TEditStream = record
15.     dwCookie: Longint;
16.     dwError: Longint;
17.     pfnCallback: TEditStreamCallBack;
18.   end;
19.  
20. // RichEdit Type
21. type
22.   TMyRichEdit = TRxRichEdit;
23.  
24. // EditStreamInCallback callback function
25. function EditStreamInCallback(dwCookie: Longint; pbBuff: PByte;
26.   cb: Longint; var pcb: Longint): DWORD; stdcall;
27.   // by P. Below
28. var
29.   theStream: TStream;
30.   dataAvail: LongInt;
31. begin
32.   theStream := TStream(dwCookie);
33.   with theStream do
34.   begin
35.     dataAvail := Size - Position;
36.     Result := 0;
37.     if dataAvail <= cb then
38.     begin
39.       pcb := read(pbBuff^, dataAvail);
40.       if pcb <> dataAvail then
41.         Result := UINT(E_FAIL);
42.     end
43.     else
44.     begin
45.       pcb := read(pbBuff^, cb);
46.       if pcb <> cb then
47.         Result := UINT(E_FAIL);
48.     end;
49.   end;
50. end;
51.  
52. // Insert Stream into RichEdit
53. procedure PutRTFSelection(RichEdit: TMyRichEdit; SourceStream: TStream);
54.   // by P. Below
55. var
56.   EditStream: TEditStream;
57. begin
58.   with EditStream do
59.   begin
60.     dwCookie := Longint(SourceStream);
61.     dwError := 0;
62.     pfnCallback := EditStreamInCallBack;  // ***missing parameter calls***
63.   end;
64.   RichEdit.Perform(EM_STREAMIN, SF_RTF or SFF_SELECTION, Longint(@EditStream));
65. end;
66.  
67. // Convert Bitmap to RTF Code
68. function BitmapToRTF(pict: TBitmap): string;
69. // by D3k
70. var
71.   bi, bb, rtf: string;
72.   bis, bbs: Cardinal;
73.   achar: ShortString;
74.   hexpict: string;
75.   I: Integer;
76. begin
77.   GetDIBSizes(pict.Handle, bis, bbs);    // unique to RxRichEdit
78.   SetLength(bi, bis);
79.   SetLength(bb, bbs);
80.   GetDIB(pict.Handle, pict.Palette, PChar(bi)^, PChar(bb)^);  // unique to RxRichEdit
81.   rtf := '{\rtf1 {\pict\dibitmap ';
82.   SetLength(hexpict, (Length(bb) + Length(bi)) * 2);
83.   I := 2;
84.   for bis := 1 to Length(bi) do
85.   begin
86.     achar := Format('%x', [Integer(bi[bis])]);
87.     if Length(achar) = 1 then
88.       achar := '0' + achar;
89.     hexpict[I - 1] := achar[1];
90.     hexpict[I] := achar[2];
91.     Inc(I, 2);
92.   end;
93.   for bbs := 1 to Length(bb) do
94.   begin
95.     achar := Format('%x', [Integer(bb[bbs])]);
96.     if Length(achar) = 1 then
97.       achar := '0' + achar;
98.     hexpict[I - 1] := achar[1];
99.     hexpict[I] := achar[2];
100.     Inc(I, 2);
101.   end;
102.   rtf := rtf + hexpict + ' }}';
103.   Result := rtf;
104. end;
105.  
106.  
107. // Example to insert image from Image1 into RxRichEdit1
108. procedure TForm1.Button1Click(Sender: TObject);
109. var
110.   SS: TStringStream;
111.   BMP: TBitmap;
112. begin
113.   BMP := TBitmap.Create;
114.   BMP := Image1.Picture.Bitmap;
115.   SS  := TStringStream.Create(BitmapToRTF(BMP));
116.   try
117.     PutRTFSelection(RxRichEdit1, SS);
118.   finally
119.     SS.Free;
120.   end;
121. end;
122.  

Rick

[molly]

I came across this code that is supposed to work for RxRichEdit. ... I also think that it defective code... .

Code: Pascal  [Select][+][-]

1.     pfnCallback := EditStreamInCallBack;  // ***missing parameter calls***
2.  

should read (for FPC)

Code: Pascal  [Select][+][-]

1.     pfnCallback := @EditStreamInCallBack;  // ***missing parameter calls***
2.  

[skalogryz]

I came across this code that is supposed to work for RxRichEdit.

Well... instead of doing direct RTF injections, you could try to use these functions in richmemoutils.pas
  InsertImageFromFile
or
  InsertImageFromFileNoResize

[rick2691]

Looking at the code that I recently posted, I noticed that the function BitmapToRTF is building place holder for the image within the RTF file code.

InDelInline is not building that code. What it inserts is {\pict\wmetafile0}, which means there was noting to insert. Normally it would be something like the following...

{\pict\wmetafile8\picwgoal5550\pichgoal4560
0100090000033afc0100000024fc01000000050000000b0200000000050000000c025a1a222324
fc0100430f2000cc000000ff005401000000005a1a2223000000002800000054010000ff000000

It starts with wmetafile8 instead of wmetafile0, and the numbers and alphabet are what the function BitmapToRTF builds.

When I copied and pasted the full body of the wmetafile8 to replace the wmetafile0 series, it loaded, was resizable, and could be saved.

It seems that all you need is to improvise a similar function to BitmapToRTF.

Rick

[skalogryz]

It seems that all you need is to improvise a similar function to BitmapToRTF.

That's another hack, that I'd like to avoid. However, you're free to use it.

[rick2691]

OK. Everything that I have researched states that RichEdit was never built to do images. To have them you have to "hack" or do a "workaound." If it is done properly it works. Not because of RichEdit, but on account of modern RTF methods.

Rick

[skalogryz]

OK. Everything that I have researched states that RichEdit was never built to do images.

Not exactly so.
Windows RichEdit is designed to embed OLE objects.
OLE used to be ...and infact is ... Windows backbone technology, and microsoft used it heavily back in the days (switching to .NET in 2000s).
Thus, RichEdit was designed with OLE objects in mind, even for simple stuff like links of images.

In the most recent versions of RichEdit (i think starting Windows 10), there's a special non OLE API to embed an image. (Which is not applicable for earlier versions of Windows), so the only cross-Windows solution is to use OLE.
Which is done by Inline objects... however, since the documentation on RichEdit internals is quite poor, lots of the development is a guess work.

To have them you have to "hack" or do a "workaound."

That's a common practice that has been in use since Delphi RichEdit days.
Yet again, I'm not going to use it with the official RichMemo inline objects, but anyone else are free to use it, since it works perfectly fine for all the small needs.
Please note that you don't have to use inline objects at all at this point.

[tk]

OK. Everything that I have researched states that RichEdit was never built to do images.

That I would not say, but you might try KMemo http://tkweb.eu/en/delphicomp/kmemo.html, it should be able to handle them fine already (I mean the newest repo download).

[rick2691]

Very well, and it is only an argument, but there is a difference between "capacity" and "functionality". Windows built RichEdit with capacity, but not for functionality. The actual production of functionality was being reserved for them. That is how you make money.

To be "cross-platform" with RichMemo you have to develop the functionality. Moreover, it needs to not be dependent on the limitations of RichEdit. It needs to be RTF driven.

Inserting the RTF code for an image is simply complying with RTF rules.

Rick