delphi - Tvirtuaildrawtree how to place nodes in one row? -

this follow other question here.

as have been suggested in comment ask new question subject

i have been suggested draw different images in row . goal beginning insert nodes side side have been told cannot done vdt not made purpose . makes me sure there way because see online project doing using same vdt

here screen shot project

with using resource viewer pe explorer found data of form

    object vdt: tvirtualdrawtree       alignwithmargins = true       left = 5       top = 5       width = 457       height = 227       margins.left = 5       margins.top = 5       margins.right = 5       margins.bottom = 5       align = alclient       bevelinner = bvnone       bevelouter = bvnone       defaultnodeheight = 55       header.autosizeindex = 0       header.font.charset = default_charset       header.font.color = clwindowtext       header.font.height = -11       header.font.name = 'tahoma'       header.font.style = []       hotcursor = crhandpoint       taborder = 0       treeoptions.paintoptions = [tohidefocusrect, tohideselection, tohottrack, toshowbuttons, toshowdropmark, tothemeaware, touseblendedimages, toalwayshideselection, touseblendedselection]       treeoptions.selectionoptions = [toextendedfocus, tomiddleclickselect, torightclickselect]       onbeforecellpaint = vdtbeforecellpaint       ongetnodewidth = vdtgetnodewidth       onmouseup = vdtmouseup       explicitleft = 3       explicittop = 3       columns = <         item           position = 0           width = 54           widetext = '55'         end         item           position = 1           width = 54           widetext = '55'         end         item           position = 2           width = 54           widetext = '55'         end         item           position = 3           width = 54           widetext = '55'         end         item           position = 4           width = 54           widetext = '55'         end         item           position = 5           width = 54           widetext = '55'         end         item           position = 6           width = 54           widetext = '55'         end         item           position = 7           width = 54           widetext = '55'         end>     end   end 

so told self have use tviruaildrawtree same goal start create data

type   tanmiclass = class   private     fanmigraphic : tgifimage;    public     property anmigraphic: tgifimage read fanmigraphic write fanmigraphic;    public     constructor create;     destructor destroy; override;   end;  type   panimedata = ^tanimedata;    tanimedata = record     fobject: tanmiclass;   end; 

as thinking have create image object node because downloading image list url add them node following , following code downloading images stringlist desk load node tgifimage

for := 0 animationimages.count-1 begin animaturl := animationimages.strings[i];  uri := tiduri.create(animaturl); try imagename := uri.document; freeandnil(uri); end;  if (extractfileext(imagename) = '.gif') begin addanimation(animaturl); end; end;  procedure tform2.addanimation(aanimationurl: string); var anmiclass: tanmiclass; path: string; begin  vdtani.beginupdate; try anmiclass := tanmiclass.create;  path := aanimationurl;  if fileexists(path) begin anmiclass.anmigraphic.loadfromfile(path); anmiclass.anmigraphic.animate := true; anmiclass.anmigraphic.transparent := true; end;  addanmitovd(vdtani, nil, anmiclass);  vdtani.endupdate; end; 

and here how draw nodes inside vdt

procedure tform2.vdtanibeforecellpaint(sender: tbasevirtualtree;   targetcanvas: tcanvas; node: pvirtualnode; column: tcolumnindex;   cellpaintmode: tvtcellpaintmode; cellrect: trect; var contentrect: trect); var data: panimedata; newrect: trect; r: trect; begin // if not assigned(node) begin exit; end;  data := vdtani.getnodedata(node);  case column of  0 : begin newrect := contentrect; newrect.left := newrect.left +2; newrect.width := 55; newrect.height := 55; newrect.top := newrect.top + 2; newrect.bottom := newrect.bottom; targetcanvas.stretchdraw( newrect, data.fobject.anmigraphic); end;  end; end; 

but cannot arrange nodes same image show above

and seems not thing can made in onbeforecellpanit .

in other question tom brunberg suggested divide images 10 nodes if image added 80 , need 8 per row example, each having 8 images , each image displayed in own column. don't know how in coding or start .

issue of current code

unit unit1;  interface  uses   winapi.windows, winapi.messages, system.sysutils, system.variants, system.classes, vcl.graphics,   vcl.controls, vcl.forms, vcl.dialogs, virtualtrees, gifimg, vcl.stdctrls,   vcl.grids, vcl.extctrls;   type   timageobjarr = array of tgifimage;   type   tanidataclass = class   imageobjarr: timageobjarr;   private     fanirefrence: string;     faniimage: tgifimage;   public     property anirefrence: string read fanirefrence write fanirefrence;     property aniimage: tgifimage read faniimage write faniimage;    public     constructor create;     destructor destroy; override;   end;  type panidata = ^tanidata;  tanidata = record fobject: tanidataclass; end;       type   tform1 = class(tform)     vdtani: tvirtualstringtree;     button1: tbutton;     button2: tbutton;     procedure button1click(sender: tobject);     procedure formshow(sender: tobject);     procedure formdestroy(sender: tobject);     procedure vdtanibeforecellpaint(sender: tbasevirtualtree;       targetcanvas: tcanvas; node: pvirtualnode; column: tcolumnindex;       cellpaintmode: tvtcellpaintmode; cellrect: trect; var contentrect: trect);     procedure formcreate(sender: tobject);     procedure vdtanifreenode(sender: tbasevirtualtree; node: pvirtualnode);     procedure vdtanigetnodedatasize(sender: tbasevirtualtree;       var nodedatasize: integer);   private     { private declarations }    imageobjarr: timageobjarr;  // main storage of images   public     { public declarations }       dimagelist : tstringlist;   end;  var   form1: tform1;  implementation  {$r *.dfm}  { tanidataclass }  constructor tanidataclass.create; begin faniimage := tgifimage.create; end;  destructor tanidataclass.destroy; begin faniimage.free;   inherited; end;  procedure tform1.button1click(sender: tobject); var   node: pvirtualnode;   data: panidata;   i, row, col: integer;   fn: string; begin    // load images main store imgarr setlength(imageobjarr, dimagelist.count);  := 0 dimagelist.count -1 begin fn := dimagelist[i]; imageobjarr[i] := tgifimage.create; imageobjarr[i].loadfromfile(fn); end;    // setup vdt nodes , assign images 8 in row   // hardcoded now. may want add dynamics   // varying window , image sizes   row := 0;   while row <= (dimagelist.count div 8)   begin     node := vdtani.addchild(nil);     data := vdtani.getnodedata(node);     setlength(data.fobject.imageobjarr, 8);     col := 0 7       data.fobject.imageobjarr[col] := imageobjarr[row * 8 + col];     inc(row);   end;  end;   procedure tform1.formcreate(sender: tobject); begin dimagelist :=  tstringlist.create; vdtani.nodedatasize := sizeof(tanidata); end;  procedure tform1.formdestroy(sender: tobject); begin if assigned(dimagelist) begin   freeandnil(dimagelist); end; end;  procedure tform1.formshow(sender: tobject); begin  dimagelist.add('1mm.gif'); dimagelist.add('2mm.gif'); dimagelist.add('3mm.gif'); dimagelist.add('4mm.gif'); dimagelist.add('5mm.gif'); dimagelist.add('6mm.gif');   end;  procedure tform1.vdtanibeforecellpaint(sender: tbasevirtualtree;   targetcanvas: tcanvas; node: pvirtualnode; column: tcolumnindex;   cellpaintmode: tvtcellpaintmode; cellrect: trect; var contentrect: trect); var   data: panidata; begin if not assigned(node) begin exit; end;    data := vdtani.getnodedata(node);   sender.nodeheight[node] := 54;   cellrect.height := 54;    targetcanvas.stretchdraw( cellrect, data.fobject.imageobjarr[column]); end;  procedure tform1.vdtanifreenode(sender: tbasevirtualtree; node: pvirtualnode); var data: panidata; begin data := vdtani.getnodedata(node); if assigned(data) data.fobject.free; end; procedure tform1.vdtanigetnodedatasize(sender: tbasevirtualtree;   var nodedatasize: integer); begin nodedatasize := sizeof(tanidata); end;  end. 

i got exception here @ following code added 6 images path string list try draw on each columns

row := 0;   while row <= (dimagelist.count div 2)   begin     node := vdtani.addchild(nil);     data := vdtani.getnodedata(node);     setlength(data.fobject.imageobjarr, 2);     col := 0 7       data.fobject.imageobjarr[col] := imageobjarr[row * 2 + col];     inc(row);   end; 

here's implementation of suggested.

type   timgarr = array of tbitmap;    tvdtdata = record     fobject: timgarr;   end;   pvdtdata = ^tvdtdata;    tform2 = class(tform)     vdt: tvirtualdrawtree;     ...   private     { private declarations }     imgarr: timgarr;  // main storage of images  implementation  procedure tform2.button1click(sender: tobject); var   node: pvirtualnode;   data: pvdtdata;   p: pointer;   i, row, col: integer;   fn: tfilename; begin   // load images main store imgarr   setlength(imgarr, 100);   := 0 99   begin     fn := format('c:\tmp\nums\%.2d.bmp',[i]);     imgarr[i] := tbitmap.create;     imgarr[i].loadfromfile(fn);   end;    // setup vdt nodes , assign images 8 in row   // hardcoded now. may want add dynamics   // varying window , image sizes   row := 0;   while row <= (100 div 8)   begin     node := vdt.addchild(nil);     p := node.getdata;     data := vdt.getnodedata(node);     // setlength(data.fobject, 8);     setlength(data.fobject, vdt.header.columns.count);     col := 0 7       data.fobject[col] := imgarr[row * 8 + col];     inc(row);   end; end;  procedure tform2.vdtbeforecellpaint(sender: tbasevirtualtree;   targetcanvas: tcanvas; node: pvirtualnode; column: tcolumnindex;   cellpaintmode: tvtcellpaintmode; cellrect: trect; var contentrect: trect); var   data: pvdtdata; begin   if not assigned(node) exit;    data := vdt.getnodedata(node);   sender.nodeheight[node] := 64;   cellrect.height := 64;    if assigned(data.fobject[column])     targetcanvas.stretchdraw( cellrect, data.fobject[column]); end; 

no warranty of not carrying errors.

and result

but seriously, others have pointed out, easier use tdrawgrid or tstringgrid. of course it's call.