Re: Can't show gif image in a rtf file

Author

Message

Norma Zhao

Posted: 03/01/2004 2:32:40

"Sergey Tkachenko" <svt@trichview.com> wrote:

>> Hi,

>> I am writing a application to allow user create a template document and

>then

>> generate the document on fly using the data and images stored in database.

>> I have two questions:

>> 1) when user insert a image into the template using RVEditor, can I add

>some

>> Identifier (eg \ImgIDxxxx ) into the rtf file so that I can replcae the

>image

>> later?

>You can only change saving images in RTF completely in OnSaveItemToFile.

>Check if the saved item is a graphic item, and SaveFormat=rvsfRTF, and

>return a code to save in OutStr.

>you can use

>procedure RVSaveImageToRTF(Stream: TStream; TwipsPerPixel: Double;

> Image: TGraphic; ImageWidth, ImageHeight: Integer; Options:

>TRVRTFOptions);

>defined in RVItem.pas to save image RTF code in Stream.

>TwipsPerPixel parameter can be get as

> function GetTwipsPerPixel: Double;

> var DC: HDC;

> begin

> DC := CreateCompatibleDC(0);

> if RichViewPixelsPerInch>0 then

> Result := (72*20) / RichViewPixelsPerInch

> else

> Result := (72*20) / GetDeviceCaps(DC, LOGPIXELSY);

> DeleteDC(DC);

> end;

Thanks Sergey.

Now I can add the identifier into the rtf file. The rtf looks like: ...

\ImageIdXXX {\pict...}...

But after resizing the dummy image (I will use the dummy image size to control

the replacement image size) the inserted identifier ('\ImageIdXXX') disappeared.

How can I avoid this happen?

>> 2) When I replace the image with a gif image, I add

>> {\pict\pngblip

>> 47494638376194023603F00000000000FFFFFF2C000000.....} into the rtf file.

>MSWord

>> can display this rtf with gif image showing OK. But when I load this rtf

>> into the Demo ActionTest.exe, the gif images were missing. JPEG image

>> OK. I am using Delphi5. I can insert and display a gif image using

>TrvActionInsertPicture.

>As you can see from the name of keyword, gif image is saved as PNG inside

>RTF

>(MS Word saves such images both as PNG and as Metafile, so TRichView reads

>and inserts metafile image).

>Unfortunately, Delphi does not have standard implementation of PNG images.

>But if you will use a third party PNG class, you can read it from RTF.

>The example was posted in trichview.support.examples several months ago

>only corrected the declaration of RichViewEdit1CustomImageItem because a

new

>parameter was added to the event)

><<

>RTF files can contain graphics in the following format: bitmap, metafile,

>jpeg, png.

>Import/export of all these formats except for png are supported by TRichView

>directly.

>But PNG is not, because Delphi does not offer standard implementation of

>png.

>But with help of events you can save and load PNG images in RTF.

>Why PNG? PNG offers a good compression. While True-Color bitmaps can be

>really huge (especially considering the fact that image size in RTF is twice

>larger than in a graphic file), PNG can be by hundreds times smaller.

>PNG images are supported by Word97 and newer. When Word saves a PNG image,

>at also saves a metafile duplicate allowing less advanced applications to

>read this image.

>The example below does not save a duplicate, because the main reason why

you

>may wish to use PNG is to make more compact RTF code.

>This example uses a free PNG class by Gustavo Huffenbacher Daud:

>http://pngdelphi.sourceforge.net/

>uses RVRTF, RVRTFProps, RVItem, CRVData, RVFMisc;

>1) Reading PNG. Can be useful even if you do not want to export images in

>RTF as PNGs

>Create a form's procedure:

>procedure TForm3.RichViewEdit1CustomImageItem(RVData: TCustomRVData;

> Graphic: TGraphic; Hypertext: Boolean; var item: TCustomRVItemInfo;

> var FreeGraphic: Boolean; RTFPicture: TRVRTFPicture;

> var Name: String);

>var png: TPngObject;

>begin

> if RTFPicture.PicType=rtf_pict_PNG then begin

> png := TPngObject.Create;

> try

> png.LoadFromStream(RTFPicture.FData);

> Graphic := png;

> FreeGraphic := True;

> except

> png.Free;

> end;

> if Graphic=nil then

> exit;

> if Hypertext then

> item := TRVHotGraphicItemInfo.CreateEx(RVData, Graphic, rvvaBaseline)

> else

> item := TRVGraphicItemInfo.CreateEx(RVData, Graphic, rvvaBaseline);

>end;

>In Form's OnCreate, assign it to

>RichViewEdit1.RTFReadProperties.OnCustomImageItem:

>RichViewEdit1.RTFReadProperties.OnCustomImageItem :=

>RichViewEdit1CustomImageItem;

>2) Writing PNG. This code will save all bitmaps and PNG in document in RTF

>as PNG.

>Event RichViewEdit1S.OnSaveItemToFile

>procedure TForm3.RichViewEdit1SaveItemToFile(Sender: TCustomRichView;

> const Path: String; RVData: TCustomRVData; ItemNo: Integer;

> SaveFormat: TRVSaveFormat; Unicode: Boolean; var OutStr: String;

> var DoDefault: Boolean);

>var Stream: TMemoryStream;

> gr: TGraphic;

> png: TPngObject;

> item : TRVGraphicItemInfo;

>begin

> if (SaveFormat<>rvsfRTF) then

> exit;

> if (RVData.GetItemStyle(ItemNo)<>rvsPicture) and

> (RVData.GetItemStyle(ItemNo)<>rvsHotPicture) then

> exit;

> item := TRVGraphicItemInfo(RVData.GetItem(ItemNo));

> gr := item.Image;

> if not (gr is TBitmap) and not (gr is TPngObject) then

> exit;

> if (gr.Width=0) or (gr.Height=0) then

> exit;

> if gr is TBitmap then begin

> png := TPNGObject.Create;

> png.Assign(gr);

> end

> else

> png := TPNGObject(gr);

> try

> Stream := TMemoryStream.Create;

> try

> png.SaveToStream(Stream);

> OutStr := Format('{\pict\pngblip\picw%d\pich%d',

>[png.Width,png.Height]);

> if item.ImageWidth>0 then

> OutStr := Format('%s\picscalex%d', [OutStr,

>Round(item.ImageWidth*100/png.Width)]);

> if item.ImageHeight>0 then

> OutStr := Format('%s\picscaley%d', [OutStr,

>Round(item.ImageHeight*100/png.Height)]);

> OutStr := OutStr+' '+RVFSavePicture(png)+'}';

> DoDefault := False;

> finally

> Stream.Free;

> end;

> finally

> if png<>gr then

> png.Free;

> end;

>end;