Delphi TGridLayout iOS gallery scroll - ios

I have gotten some results trying to use TGridLayout to hold series of TImage object each with a bitmap loaded. However, I seem unable to scroll the control? I thought about placing it on a scrollbox, but then I would need a way to size the height of TGridLayout

procedure TForm1.VertScrollBox0Resize(Sender: TObject);
var s:string; i, x,y:integer;
begin
i := VertScrollBox0.tag; //imagecounts
Gridlayout1.Width := VertScrollBox0.Width;
x := round( Gridlayout1.Width/Gridlayout1.ItemWidth);
y := round (Gridlayout1.Tag /x ) ;
Gridlayout1.Height := y * Gridlayout1.ItemHeight+(2* Gridlayout1.ItemHeight );
end;

Related

Filling blank space in delphi stringgrid

I have a grid that can be resized. And i'm now stuggeling with filling the blank space around columns in the grid. I'm trying to achieve this on FormResize.
First i calculate what is the total of columns width and then i'm comparing it to the string grid width. if the stringgrid widths is bigger then i add to each columns width equal portions of the blank space left. This is how it looks in formResize Procedure:
procedure TBDDTool.FormResize(Sender: TObject);
var
totColWidth,i : integer;
begin
totColWidth := 0;
for i := 0 to sgFilePreview.ColCount - 1 do
totColWidth := totColWidth + sgFilePreview.ColWidths[i];
if sgFilePreview.Width > TotColWidth then
begin
for i := 0 to sgFilePreview.ColCount - 1 do
begin
sgFilePreview.ColWidths[i] := round(sgFilePreview.ColWidths[i] +
((sgFilePreview.Width - totColWidth)/(sgFilePreview.colCount)));
end;
end;
end;
This actualy doesn't work cause sgFilePReview.Width is the width of my grid. And i don't know how to get the width of the whole space inside the grid, like every columns + blank space left. How can i get the real width of the grid? Cause sgFilePreview.Width return the width of the grid but as seen from outside the grid.
Thank you!
EDIT
Addine new columns
for val in sLineSplitted do
begin
if Pos('#',val) <> 0 then propVal := copy(val,0,pos('#',val)-1)
else propVal := val;
col := col +1;
if (row = 1) then
begin
if (col >1) then
//Add column
sgFilePreview.ColCount := col;
sgFilePreview.Cols[col-1].Text := propVal;
SetLength(aSourceData[row-1],col);
aSourceData[row-1,col-1] := val;
end
else
begin
sgFilePreview.RowCount := row;
SetLength(aSourceData[row-1],col);
aSourceData[row-1, col-1] := val;
sgFilePreview.Cells[col-1, row-1] := propVal;
pnlFileManager.Visible := true;
end;
end;
Auto size columns to fit word if the world is bigger than the cell's width
procedure TBDDTool.AutoSizeGrid(Grid: TStringGrid);
const
ColWidthMin = 10;
var
C,R,W, ColWidthMax: integer;
begin
for c := 0 to Grid.ColCount - 1 do
begin
ColWidthMax := ColWidthMin;
for R := 0 to Grid.RowCount - 1 do
begin
W := Grid.Canvas.TextWidth(Grid.Cells[C,R]);
if W > ColWidthMax then
ColWidthMax :=W;
end;
Grid.ColWidths[C] := ColWidthMax +5;
end;
end;
The main problem why these empty spaces are occurring to you even when you have too many columns so that all of them can be seen at the same time is the fact that in StringGrid scrolling works a bit different than you are used to in other controls.
When you scroll around in StringGrid the scrolling position is always aligned to the position of TopLeft visible cell. So if the combined width of visible cols isn't the same as ClientWidth this means that you will either have partially visible col at the right side or and empty space when you have scrolled all the way to the right.
Now one possible way to avoid this is to resize the columns so that they always fit into the client width (no partially visible columns). But the problem is that this becomes practically impossible if you have different widths for each column.
In case if you can live with the fact that all columns will have same width you can use the code below which works in most cases. It isn't perfect because you can only set column width to integer values where sometimes you would need larger precision.
procedure TForm1.FormResize(Sender: TObject);
var cwDefaultWidth: Integer;
VisibleCols: Integer;
ColWidth: Integer;
begin
cwDefaultWidth := 64;
VisibleCols := StringGrid1.ClientWidth div cwDefaultWidth;
if VisibleCols >= StringGrid1.ColCount then
begin
ColWidth := Round(StringGrid1.ClientWidth / StringGrid1.ColCount-1);
end
else
begin
ColWidth := Round(StringGrid1.ClientWidth / VisibleCols-1);
end;
StringGrid1.DefaultColWidth := ColWidth;
end;
But if you are using variable column widths then the only thing that you could do is adjust the size of the last column so that it's width fills the empty space that would otherwise appear.
In order to do that you would first have to check to see if you are scrolled fully to the right. Then you would have to sum up the width of currently seen columns. You could do this by using:
for I := StringGrid1.LeftCol to StringGrid1.RowCount-1 do
begin
VisibleColsWidth := VisibleColsWidth + StringGrid1.ColWidths[I];
end;
Then you subtract this width from StringGrid1.ClientWidth and you get the width of empty space. So finally you increase the size of last column for the empty space width.
I really hope that even if my answer doesn't provide you with an actual solution it would at least guide you towards finding the right solution.

Trouble synchronizing generic TList and TListBox

I have trouble keeping a TListbox in sync with a TList. Each time an item is added to a generic TList, OnNotify is called and the callback calls just one procedure: create_gradients. Its code is below:
procedure TColor_Dialog.create_gradients;
var Editor: TGradient_Editor;
eGradient: Int32;
y: single;
s: string;
begin
List_Names.Clear;
List_Gradients.Clear;
for eGradient := 0 to FColor_Editor.nGradients - 1 do
begin
List_Names.Items.Add (FColor_Editor [eGradient].Check_Rainbow.Text);
end; // for
List_Gradients.BeginUpdate;
try
for eGradient := 0 to FColor_Editor.nGradients - 1 do
begin
Editor := FColor_Editor [eGradient];
y := (eGradient + 1) * Editor.Height;
Editor.Position.Y := y;
s := Editor.Check_Rainbow.Text;
List_Gradients.AddObject (Editor);
end; // for
finally
List_Gradients.EndUpdate;
end; // try..finally
end; // create_gradients //
As you see it simply enumerates all items in the list. Each item in the list is a TGradient_Editor which in turn has TFrame as a parent. On the parent are some FMX controls as combolorboxes, an image and a checkbox (Check_Rainbow). Check_Rainbow.Text is used for identification purposes. When the gradient editor is created, it creates a unique name from frame_%s where %s is a sequence number that is incremented each time a gradient editor is created. Owner and Parent are both List_Gradients.
From the image above you can see what happens. the listbox on the right is added for checking and just shows the text's, which is the correct sequence by the way. When I use the debugger to follow the addition of the gradient editors to List_Gradient they are processed in the same order. But the order of the gradient editors is wrong. I have to mention that the aligment of the gradient editors is alTop. I added even some code to ensure that the editor is Positioned at the very bottom of the List_Gradients.
I appear not to understand something. I cannot imagine that sequential adding to a TListBox cannot result in the correct order. What am I doing wrong?
Try this instead:
procedure TColor_Dialog.create_gradients;
var
Editor: TGradient_Editor;
eGradient: Int32;
y: single;
begin
List_Names.Clear;
List_Gradients.Clear;
for eGradient := 0 to FColor_Editor.nGradients - 1 do
begin
List_Names.Items.Add (FColor_Editor[eGradient].Check_Rainbow.Text);
end;
List_Gradients.BeginUpdate;
try
y := 0.0; // or whatever value you want to start at...
for eGradient := 0 to FColor_Editor.nGradients - 1 do
begin
Editor := FColor_Editor[eGradient];
Editor.Position.Y := y;
List_Gradients.AddObject(Editor);
y := y + Editor.Height;
end;
finally
List_Gradients.EndUpdate;
end;
end;
As requested I moved the answer to this section. The correct code is:
procedure TColor_Dialog.create_gradients;
var Editor: TGradient_Editor;
eGradient: Int32;
y: single;
begin
List_Gradients.BeginUpdate;
try
List_Gradients.Clear;
y := 0;
for eGradient := 0 to FColor_Editor.nGradients - 1 do
begin
Editor := FColor_Editor [eGradient];
Editor.Position.X := 0;
Editor.Position.Y := y;
Editor.Width := List_Gradients.Width;
List_Gradients.AddObject (Editor);
y := y + Editor.Height;
end; // for
finally
List_Gradients.EndUpdate;
end; // try..finally
end; // create_gradients //
and not using any alignment anymore. Adding Objects to a TListBox is a real nice feature of FMX. However, be prepared that things sometimes work differently than you expect. For one thing: objects are not positioned in the same way as strings.

ListView Column Resize in Delphi XE4

I face a issue with dynamically resizing the column width of a TJVListview in Delphi XE4 (in Windows 7 environment). Application takes longer time for column resize and sometimes throws access violation if there are huge data on the listview. We are using the below code for resizing the columns.
for i := 0 to LV.Columns.Count -1 do
begin
if LV.Columns.Items[i].Tag = 0 then
begin
LV.Columns.Items[i].Width := ColumnTextWidth;
LV.Columns.Items[i].Width := ColumnHeaderWidth;
end;
end;
Previously the same code used to work fine with Delphi 2009. The problem I noticed only when we are using customdrawitem event(Where we are placing images inside the listview). For the normal listview with only text display the above code is working fine.
I tried using the Column AutoSize property by setting it true, but it is of no use.
Any suggestion on how to overcome this issue. Actually, we are using the TJVlistview component in number of places in our application.
Regards,
Siran.
cODE :
1) In my form I have a JVListview, Button and imagelist. Button for loading into List view.
2) in Advancecustomdrawitem, I try to place a BMP control and also perform alternative row color change...
procedure TForm1.Button1Click(Sender: TObject);
var
i, ii: Integer;
ListItem: TListItem;
strVal : String;
begin
strVal := 'Test String';
try
ListView.Items.BeginUpdate;
LockWindowUpdate(listview.handle);
try
ListView.Clear;
for i := 1 to 15 do
begin
ListItem := ListView.Items.Add;
ListItem.SubItems.Add(strVal +'_' +IntToStr(i));
ListItem.SubItems.Add(strVal +'_' +IntToStr(i));
ListItem.SubItems.Add(strVal +'_' +IntToStr(i));
ListItem.SubItems.Add(strVal +'_' +IntToStr(i));
ListItem.SubItems.Add(strVal +'_' +IntToStr(i));
end;
finally
// for resizing the columns based on the text size
FitToTextWidth(ListView);
ListView.Items.EndUpdate;
LockWindowUpdate(0);
end;
except
on E: Exception do
MessageDlg(PWideChar(E.Message), TMsgDlgType.mtError, [TMsgDlgBtn.mbOK], 0);
end;
end;
procedure TForm1.FitToTextWidth(LV: TListView);
var
i : integer;
begin
// Set the Column width based on based on textwidth and headerwidth
for i := 0 to LV.Columns.Count -1 do
begin
if LV.Columns.Items[i].Tag = 0 then
begin
LV.Columns.Items[i].Width := ColumnTextWidth;
LV.Columns.Items[i].Width := ColumnHeaderWidth;
end;
end;
end;
procedure TForm1.LISTVIEWAdvancedCustomDrawItem(Sender: TCustomListView;
Item: TListItem; State: TCustomDrawState; Stage: TCustomDrawStage;
var DefaultDraw: Boolean);
Var
R : TRect;
C : TCanvas;
B : TBitMap;
begin
// Set C
C := (Sender as TListView).Canvas;
// Set R
R := Item.DisplayRect(drLabel);
B := TBitMap.Create;
B.Transparent := True;
B.TransparentColor := clWhite;
// based on item index set the image and change the row color
if odd(item.Index) = true then
begin
ImageList.GetBitmap(0,B);
TJvListItem( Item ).Brush.Color := clWhite;
TJvListItem( Item ).Font.Color := clBlack;
end
else
begin
ImageList.GetBitmap(1,B);
TJvListItem( Item ).Brush.Color := clMoneyGreen;
TJvListItem( Item ).Font.Color := clBlack;
end;
C.Draw(R.Left + 5 ,R.Top, B);
B.Free;
end;
The above code works well with Delphi 2009... but currently trying migrating to XE4 in Win 7 environment.. my problem here is, it takes lot of time in loading the list view (When performing column resizing dynamically by calling FitToTextWidth method) .. but without this method it is working fine but without column resizing...
When you set the width of a column to any one of the automatic constants, the control have to evaluate the length of the items/subitems to be able to calculate the necessary width. This takes time.
Also, when you set the width of a column, the VCL ListView updates all columns.
You have six columns, setting the width of any one of them involves 6 column updates, together with the spurious call in your FitToTextWidth procedure, your code is causing reading all items/subitems of a column 42 times (due to the code path in VCL: 1 time for 1st col, 2 times for 2nd -> 21 times for setting the width of 6 columns). Enclose your width setting in Begin/EndUpdate calls and remove the extra call, and you'll finish it in 6 rounds.
procedure TForm1.FitToTextWidth(LV: TListView);
var
i : integer;
begin
// Set the Column width based on based on textwidth and headerwidth
LV.Columns.BeginUpdate;
try
for i := 0 to LV.Columns.Count -1 do
begin
if LV.Columns.Items[i].Tag = 0 then
begin
// LV.Columns.Items[i].Width := ColumnTextWidth;
LV.Columns.Items[i].Width := ColumnHeaderWidth;
end;
end;
finally
LV.Columns.EndUpdate;
end;
end;
As I don't get any AV with your test case, I cannot comment on that.

Dynamic TImage's in dynamic TPanel's?

OK, I'm trying to create some custom number of TPanel's at runtime on TScrollBox surface like you can see on following image.
To get this I'm using following code and that works fine.
var
pan: array of TPanel;
maxp, i, x, y: Integer;
...
maxp := 10;
SetLength(pan, maxp);
for i := 1 to maxp do begin
// x is correct value; doesn't cause problem
// y is correct value; doesn't cause problem
pan[i-1] := TPanel.Create(form1);
with pan[i-1] do begin
Width := 100;
Height := 150;
Top := x * 151;
Left := y * 101;
Parent := ScrollBox1;
end;
end;
Now, I have problems to put TImage object in every TPanel with same index (img[0] -> pan[0], img[1] -> pan[1], etc). Look at the following image:
Using same logic, I've tried to create TImage's but w/ no success.
I'm using this code and cant figure out what's wrong. It looks so simple to me, but somehow it doesn't provide expected effect.
var
pan: array of TPanel;
img: array of TImage;
maxp, i, x, y: Integer;
...
maxp := 10;
SetLength(pan, maxp);
SetLength(img, maxp);
for i := 1 to maxp do begin
// x is correct value; doesn't cause problem
// y is correct value; doesn't cause problem
pan[i-1] := TPanel.Create(form1);
with pan[i-1] do begin
Width := 100;
Height := 150;
Top := x * 151;
Left := y * 101;
Parent := ScrollBox1;
end;
img[i-1] := TImage.Create(form1);
with img[i-1] do begin
Width := 98;
Left := 1;
Height := 148;
Top := 1;
// in original code next line had img[0]. which caused problem
Picture.LoadFromFile('some_image_file');
Parent := pan[i-1];
end;
end;
Somehow it places all TImage objects on same place in first TPanel (pan[0]). It's confusing for me because it says Parent := pan[i-1]; but for some reason it always puts TImage in pan[0]. I've tried using breakpoints to see what's going on after every for-loop cycle (added Application.ProcessMessages at the end) and it really creates 10 different images but puts them onto pan[0]. Of course, at the end it shows just last image loaded into pan[0].
My question is how to make one dynamic TImage per dynamic TPanel (with same array indices)?
SOLVED!
And word of advice - get rid of the with blocks. They may seem innocent and simple at first, but in the long run they only serve to write sloppy code that is hard to troubleshoot. Had you been using explicit variable references instead, this problem would never had occurred in the first place.
var
  Panels: array of TPanel;
Panel: TPanel;
  Images: array of TImage;
Image: TImage;
  maxp, i, x, y: Integer;
...
maxp := 10;
SetLength(Panels, maxp);
SetLength(Images, maxp);
for i := 1 to maxp do begin
  Panel := TPanel.Create(form1);
Panels[i-1] := Panel;
Panel.Parent := ScrollBox1;
  Panel.SetBounds(...);
  Image := TImage.Create(form1);
Images[i-1] := Image;
Image.Parent := Panel;
Image.SetBounds(...);
  Image.Picture.LoadFromFile('some_image_file');
end;
You set Height twice and no Left, so it seems.
with pan[i-1] do begin
Width := 100;
Height := 150;
Top := x * 151;
Height := y * 101;
Parent := ScrollBox1;
end;
Ah, I found it... how blind I am really...
To get auto-complete in delphi, i've used img[0] in front of Picture.LoadFromFile(). Then, obviously I forgot to remove it from code, and since hour ago that 'prefix' stayed there making all images load into same img[0]. I was sure there's something wrong with Parent or Pos/Size properties and have been focused on this things not caring so much about this.
I actually had
with img[i-1] do begin
Width := 98;
Left := 1;
Height := 148;
Top := 1;
img[0].Picture.LoadFromFile('some_image_file');
Parent := pan[i-1];
end;
But somehow I've removed that img[0] part while posting this question, and haven't seen it as problem in my Delphi code. Obviously, when I was formatting this code, i removed some parts and that made answering my question here impossible :(
Really sorry for bothering you guys, that was my bad.

How to find the actual width of grid component with scrollbar in Delphi

I have a grid component (DBGrid) which has lots of columns on it. Because of large number of columns, a scrollbar was created, and thus some part of grid remains hidden. I need to find out what is the real width of DBGrid, including the part which is not shown due to scroll bar. But Width property gives only the width of the component itself. Anybody has any idea?
TDBGrid has a Columns property. Each of the columns has its own Width property. So you could loop through all of the columns and sum up their widths.
Like this:
function TotalColumnsWidth(var AGrid: TDBGrid);
var
i: Integer;
begin
Result := 0;
for i := to AGrid.Columns.Count - 1 do
Result := Result + AGrid.Columns[i].Width;
end;
Perhaps this may be helpful. It is part of a class helper for TDBGrid that auto sizes the last column, so that the grid has no empty space. Should be easy to adjust to your needs.
As you may notice, the CalcDrawInfo method is what you are seeking for. As it is protected you can either use a class helper or the usual protected-hack to get hands on it.
procedure TDbGridHelper.AutoSizeLastColumn;
var
DrawInfo: TGridDrawInfo;
ColNo: Integer;
begin
ColNo := ColCount - 1;
CalcDrawInfo(DrawInfo);
if (DrawInfo.Horz.LastFullVisibleCell < ColNo - 1) then Exit;
if (DrawInfo.Horz.LastFullVisibleCell < ColNo) then
ColWidths[ColNo] := DrawInfo.Horz.GridBoundary - DrawInfo.Horz.FullVisBoundary
else
ColWidths[ColNo] := ColWidths[ColNo] + DrawInfo.Horz.GridExtent - DrawInfo.Horz.FullVisBoundary
end;
I think I have found a solution (although it seems a little strange). In order to find the difference between column widths and real width of the DBgrid (that means find the width of the empty space left after last column), we need to keep track of which column is shown on the left now (what is current column that is scrolled to). We can do that using OnDrawColumnCell event, since it will draw only columns which are scrolled on now. Then we need to calculate sum of widths of all visible columns, and subtract that from DBGrid's width. P.S. Sorry for bad english
Ex code:
For i:=0 to Last do
if Vis[i] then
Begin
Sum:=Sum+DBG.Columns[i].Width;
Inc(Cnt);
End;
if dgColLines in DBG.Options then
Sum := Sum + Cnt;
//add indicator column width
if dgIndicator in DBG.Options then
Sum := Sum + IndicatorWidth;
Dif:=DBG.ClientWidth - Sum;
Here are functions we have used in the past. It takes into account the width of data based on the font and also compensates for vertical lines if they are visible
function GridTextWidth(fntFont : TFont; const sString : OpenString) :
integer;
var
f: TForm;
begin
try
f:=TForm.Create(nil);
f.Font:=fntFont;
result:=f.canvas.textwidth(sstring);
finally
f.Free;
end;
end;
function CalcGridWidth(dbg : TDBGrid { the grid to meaure }): integer; { the "exact" width }
const cMEASURE_CHAR = '0';
iEXTRA_COL_PIX = 4;
iINDICATOR_WIDE = 11;
var i, iColumns, iColWidth, iTitleWidth, iCharWidth : integer;
begin
iColumns := 0;
result := GetSystemMetrics(SM_CXVSCROLL);
iCharWidth := GridTextWidth(dbg.font,cMeasure_char);
with dbg.dataSource.dataSet do begin
DisableControls;
for i := 0 to FieldCount - 1 do with Fields[i] do
if visible then
begin
iColWidth := iCharWidth * DisplayWidth;
if dgTitles in dbg.Options then begin
ititlewidth:=GridTextWidth(dbg.titlefont,displaylabel);
if iColWidth < iTitleWidth then
iColWidth := iTitleWidth;
end;
inc(iColumns, 1);
inc(result, iColWidth + iEXTRA_COL_PIX);
end;
EnableControls;
end;
if dgIndicator in dbg.Options then
begin
inc(iColumns, 1);
inc(result, iINDICATOR_WIDE);
end;
if dgColLines in dbg.Options then
inc(result, iColumns)
else
inc(result, 1);
end;

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