I'm building an app with RAD Studio 11, but I can't find a way to change the item font of my TListBox.
I tried to change TListBox.Font in the Object Inspector, but when I select my TListBox called ingredientsDataBase in the Object Inspector, I can just change TListBox settings instead of TListBox.Items settings.
I add a TListBoxItem manually as follow:
Then, I can change ListBoxItem1.Font in the Object Inspector, after selecting my ListBoxItem1 (no problem).
The problem is that, when I run my program, the Font change only affects my ListBoxItem1, and I want the same Font for every item that I add to my TListBox.
UPDATE 1
After your help I tried to convert your Delphi code to C++.
__fastcall TIngredientCreator::addButtonClick(TObject *Sender){
//More code Here
//Then I ADD a new ListBoxItem to my ListBox "ingredientsDataBase"
ingredientsDataBase->Items->Add("newIngredient");
TListBoxItem *lbItem = new TListBoxItem(ingredientsDataBase);
lbItem->Parent = ingredientsDataBase;
// Remove Family and Size from the items TStyledSettings
lbItem->StyledSettings = lbItem->StyledSettings << TStyledSetting::Family << TStyledSetting::Size;
// You can now set these TextSettings as needed
lbItem->TextSettings->Font->Family = "Algerian";
lbItem->TextSettings->Font->Size = 18;
lbItem->Text = "algerian";
delete lbItem;
}
There is no syntax error, but I can't associate my new ListBoxItem, in this case the Text or Name of that new ListBoxItem called "newIngredient" (I don't know how to do it in this code), so when I run my program nothing happen to mi new Item at least.
UPDATE 2
I found a way to associate my newIngredient to TListBoxItem Object as follow:
int index = ingredientsDataBase->Items->IndexOf(newIngredient);
lbItem = ingredientsDataBase->ItemByIndex(index);
When I run the code and I add a new Ingredient, just the Text of the newIngredient is changed to "algerian", because in the first code I have this line lbItem->Text = "algerian" all good here. But Font and Size still without change.
Thanks for your answers
When you add items to the listbox, you need to clear some items from the default StyledSettings property of the new item, if you want to modify the corresponding TextSettings.
Here's an example in Delphi to do what you want:
procedure TForm5.Button2Click(Sender: TObject);
var
lbItem: TListBoxItem;
begin
lbItem := TListBoxItem.Create(ListBox1);
lbItem.Parent := ListBox1;
// Remove Family and Size from the items TStyledSettings
lbItem.StyledSettings := lbItem.StyledSettings - [TStyledSetting.Family,TStyledSetting.Size];
// You can now set these TextSettings as needed
lbItem.TextSettings.Font.Family := 'Algerian';
lbItem.TextSettings.Font.Size := 18;
lbItem.Text := 'algerian';
// In Embarcadero C++Builder you use the ">>" operator to remove members from a set, and "<<" to include them.
end;
After your help my code in a Multi-Device Application C++ Builder project result on the next code:
__fastcall TIngredientCreator::addButtonClick(TObject *Sender){
//More code Here
//Then I ADD a new ListBoxItem to my ListBox "ingredientsDataBase"
ingredientsDataBase->Items->Add("newIngredient");
int index = ingredientsDataBase->Items->IndexOf(newIngredient);
lbItem = ingredientsDataBase->ItemByIndex(index);
// Remove Family and Size from the items TStyledSettings
lbItem->StyledSettings = lbItem->StyledSettings >> TStyledSetting::Family >> TStyledSetting::Size;
// You can now set these TextSettings as needed
lbItem->TextSettings->Font->Family = "Consolas";
lbItem->TextSettings->Font->Size = 18;
delete lbItem;
}
If you are trying to do it in a Windows VCL Aplication C++ Builder Project is easier (You can change the font of the entire TListBox once):
ingredientsDataBase->Font->Size = 8.5;
ingredientsDataBase->Font->Name = "Consolas";
I have 6 textboxes at the top of the screen that update an entire column(one textbox per column) based on any changes. I was selecting the columns based on their class (.l#). Here is the code (issues to follow):
function UpdateField() {
var ctrl = this;
var id = parseInt(ctrl.id.replace("item", ""), 10) - 1;
var bound = [".l1", ".l7", ".l8", ".l9"];
var fields = $(bound[id]);
for (var i = 0; i < fields.length; i++)
{
fields[i].innerHTML = $(ctrl).val();
}
};
which is bound to the keyup event for the text areas. Issues are:
1) initially fields.length was -1 as I didn't want to put data in the "add new
row" section at the bottom. However, when running it, I noticed the
final "real" record wasn't being populated. Also, when stepping through, I
noticed that the "new row" field was before the "last row" field.
2) when doing it this way, it is purely superficial: if I double click the field,
the real data hasn't been changed.
so in the grand scheme of things, I know that I was doing it wrong. I'm assuming it involves updating the data and then forcing a render, but I'm not certain.
Figured out how to do it. Modified the original code this way:
function UpdateField() {
var ctrl = this;
var id = parseInt(ctrl.id.replace("item", ""), 10) - 1;
var bound = ['title1', 'title2', 'title3', 'title4'];
var field = bound[id];
for (var i = 0; i < dataView.getLength(); i++)
{
var item = dataView.getItem(i);
item[field] = $(ctrl).val();
dataView.updateItem(i, item);
}
grid.invalidate();
};
I have 6 textboxes (item1-item6) that "bind" to fields in the sense that if I change data in a textbox, it updates all of the rows and any new rows added also have this data.
Parts where the two issues can be explained this way:
1) to work around that, though still it would be a presentational fix and not a real updating of the underlying data, one could force it to ignore if it had the active class attached. Extra work, and not in the "real" direction one is going for (masking the field).
2) It was pretty obvious with the original implementation (though it was all I could figure out via Chrome Dev Tools that I could modify at the time) that it was merely updating a div's content and not actually interacting with the data underneath. Would look nice, and perhaps one could just pull data from the item1-item6 boxes in place of the column if it is submitted, but if someone attempts to modify the cell, they'll be looking at the real data again.
I'm using CListCtrl with LVS_EX_CHECKBOXES style.
And I need to have at least two of the checkboxes were set checked at any time.
How can I do this?
First you need to trap the LVN_ITEMCHANGING notification, which is most easily done by deriving your own class from CListCtrl (for example, called CMyListCtrl) and then adding a message map entry like the following:
BEGIN_MESSAGE_MAP(CMyListCtrl, CListCtrl)
ON_NOTIFY_REFLECT(LVN_ITEMCHANGING, &CMyListCtrl::OnLvnItemchanging)
END_MESSAGE_MAP()
Then, you write the message handler like so:
void CMyListCtrl::OnLvnItemchanging(NMHDR *pNMHDR, LRESULT *pResult)
{
// an item has changed
LPNMLISTVIEW pNMLV = reinterpret_cast<LPNMLISTVIEW>(pNMHDR);
// by default, allow change
*pResult = 0;
// see if item was checked or unchecked
if ((pNMLV->uNewState & 0x2000) == 0x2000)
{
// item was checked - do anything you like here
}
else if ((pNMLV->uNewState & 0x1000) == 0x1000)
{
// item was unchecked - see how many selections we have
if (/* pseudocode */ number of selected items < 2)
{
// disallow change
*pResult = 1;
}
}
}
The condition is pseudo-code so you can decide how to keep track of the number of selections - maybe keep a count by adding code to the above method, or put a loop in there to get the check state of each item and make a tally.
I think this should give you enough to get moving, so please update your question if you get stuck further.
I've been searching the net for different things about the win32 API, but it seems all information on it is rather sparse.
I am looking to create a simple window that shows a list of items, however I want to display different columns of data for each item, in a table-style format, where the user could perhaps be allowed to resize the different column widths.
If at all possible, I'd like to also be able to change the background colors of different rows, in the code, between just a general white, red, yellow, or green.
And the user would also be allowed to right click different rows, and be able to call a function on them, or copy the data to the clipboard (but that part is a different story).
Now, I've found list-viewer objects(?) that can be placed in the window, buttons, and right-click menus... but I cannot figure out how to do a table, using the Win32 API. I haven't even really read up on background colors for anything other than the window itself, either.
Is there a different, better framework I should use for this, or are there some functions or items that I've been missing? All help or guidance on the idea would be appreciated...
I'm using MSVC++ to do... everything that I'm working on.
Using the windows API and the standard control ListView you can do a table using the style LVS_REPORT
documentation link - unfortunatelly with no code :( -
About List-View Controls
I've found this good article Windows Programmierung: List View
the explanation is in german language but a google translation together with the code should be enough to understand it. From the article, to create the window:
#include "commctrl.h"
InitCommonControls();
hwndList = CreateWindow(WC_LISTVIEW, "",
WS_VISIBLE|WS_BORDER|WS_CHILD | LVS_REPORT | LVS_EDITLABELS,
10, 10, 300, 100,
hWnd, (HMENU)ID_LIST, hInst, 0);
then it is explained how to create the columns in the method
int CreateColumn(HWND hwndLV, int iCol, char *Text, int iWidth)
how to insert an item (one column)
int CreateItem(HWND hwndList, char *Text)
or insert item with two columns
int Create2ColItem(HWND hwndList, char *Text1, char *Text2)
etc...
Windows provides a fairly basic collection of built-in controls, listed here.
If you want something more sophisticated your options are:
Code it yourself. You have to paint it yourself, handle all the user-interaction, the scrolling, etc. This is a big job.
Find an existing implementation.
Abandon VC++ and use WinForms or WPF.
If you're stuck with VC++, The Grid Control and The Ultimate Grid are MFC-based.
If you're not using MFC there's BABYGRID or The Win32 SDK Data Grid.
If none of them suit, you'll have more luck searching for "grid" than "table".
For Listview examples, nothing beats the clarity of the Classic Sample!
In the meantime, Google Translate along with Unicode + tiny modifications to the rescue for #Alejadro's German link for the Listview- there's no direct translation on offer from search results as the page doesn't contain the appropriate meta tag. Snipped a little for brevity:
Subsequent changes of styles
The style of a ListView can be changed after creation. For this the functions GetWindowLong and SetWindowLong are used. About masks different styles can be defined.
Mask.................................Masked Styles:
LVS_TYPEMASK..............LVS_ICON, LVS_LIST, LVS_REPORT and LVS_SMALLICON
LVS_ALIGNMASK.............LVS_ALIGNLEFT and LVS_ALIGNTOP
LVS_TYPESTYLEMASK...LVS_ALIGNLEFT and LVS_ALIGNTOP but also VS_NOCOLUMNHEADER and LVS_NOSORTHEADER
For the following sequence, dwView contains the style to use, such as LVS_REPORT or LVS_ICON.
DWORD dwStyle = GetWindowLong(hwndLV, GWL_STYLE); // get current style
if ((dwStyle & LVS_TYPEMASK)! = dwView) // only on change
SetWindowLong(hwndLV, GWL_STYLE, (dwStyle & ~ LVS_TYPEMASK) | dwView); }
Control of the ListView control
Generating a list
A list view is created with the CreateWindow function. The window class uses the constant WC_LISTVIEW. To do this, the common control header file must be included.
#include "commctrl.h"
InitCommonControls();
hwndList = CreateWindow(WC_LISTVIEW, "",
WS_VISIBLE | WS_BORDER | WS_CHILD | LVS_REPORT | LVS_EDITLABELS,
10, 10, 300, 100,
hWnd, (HMENU) ID_LIST, hInst, 0);
In the dialog, it is simply defined in the resource.
If there are unresolved externals, you should check whether the library for the Common Controls (comctl32.lib) is included.
Columns of the ListView
Before something can be inserted in a REPORT, the columns must be defined. A column is described by the structure LVCOLUMN. The following routine creates a column.
int CreateColumn(HWND hwndLV, int iCol, char * text, intwidth)
{
LVCOLUMN lvc;
lvc.mask = LVCF_FMT | LVCF_WIDTH | LVCF_TEXT | LVCF_SUBITEM;
lvc.fmt = LVCFMT_LEFT;
lvc.cx = iWidth;
lvc.pszText = text;
lvc.iSubItem = iCol;
return ListView_InsertColumn(hwndLV, iCol, & lvc);
}
The columns can be modified by messages to the ListView or by calling macros that will ultimately execute a SendMessage.
Message Macro call Function
LVM_INSERTCOLUMN ListView_InsertColumn(HWND, int, LVCOLUMN * ) Insert column
LVM_DELETECOLUMN ListView_DeleteColumn(HWND, int) Delete column
LVM_GETCOLUMN ListView_GetColumn(HWND, int, LVCOLUMN * ) Get properties of the column
LVM_SETCOLUMN ListView_SetColumn(HWND, int, LVCOLUMN * ) Change properties of the column
LVM_GETCOLUMNWIDTH ListView_GetColumnWidth(HWND, int) Determine column width
LVM_SETCOLUMNWIDTH ListView_SetColumnWidth(HWND, int, int) Set column width
Insert a line
An element of the ListView is described by the structure LVITEMW (see below). Each element can be represented as an ICON, SMALLICON, LIST element or as the left column of a REPORT line.
int CreateItem(HWND hwndList, wchar_t * text)
{
LVITEMW lvi = {0};
lvi.mask = LVIF_TEXT;
lvi.pszText = text;
return ListView_InsertItem(hwndList, & lvi);
}
The mask field determines which elements of the LVITEMW structure are really used. Since it often makes sense to keep a pointer to the memory object that holds the data behind the object, the lParam field is useful. In order for this to be used, LVIF_TEXT | LVIF_PARAM must be set as a mask.
The constants of mask and the fields that enable them:
LVIF_IMAGE iImage
LVIF_INDENT iIndent
LVIF_PARAM lParam
LVIF_STATE state
LVIF_TEXT pszText
The further columns of a report
The element itself is always left in the report view and is selectable. To fill more columns, a text is added to the item.
int Create2ColItem(HWND hwndList, wchar_t * Text1, wchar_t * Text2)
{
LVITEMW lvi = {0};
int Ret;
// Initialize LVITEMW members that are common to all items.
lvi.mask = LVIF_TEXT;
lvi.pszText = Text1;
Ret = ListView_InsertItem(hwndList, & lvi);
if (Ret >= 0)
{
ListView_SetItemText(hwndList, Ret, 1, Text2);
}
return Ret;
}
The above Create2ColItem is best demonstrated by something along the line of the following statements:
LVHwnd = Your_Create_LV_Routine();
if (LVHwnd)
{
CreateColumn(LVHwnd, 0, ptrColHeaderString1, iColSize1);
CreateColumn(LVHwnd, 1, ptrColHeaderString2, iColSize2);
Create2ColItem(LVHwnd, ptrItemText1, ptrItemText2);
}
The structure LVITEMW
The structure LVITEMW (in CommCtrl.h) describes an element of the ListView. The most important elements are briefly described here. First the definition:
typedef struct tagLVITEMW
{
UINT mask;
int iItem;
int iSubItem;
UINT state;
UINT stateMask;
LPWSTR pszText;
int cchTextMax;
int iImage;
LPARAM lParam;
#if (_WIN32_IE >= 0x0300) //historical note for IE3 users!
int iIndent;
#endif
#if (NTDDI_VERSION >= NTDDI_WINXP)
int iGroupId;
UINT cColumns; // tile view columns
PUINT puColumns;
#endif
#if (NTDDI_VERSION >= NTDDI_VISTA)
int* piColFmt;
int iGroup; // readonly. only valid for owner data.
#endif
} LVITEMW, *LPLVITEMW;
The LVM_GETITEMW and LVM_SETITEMW messages change the attributes of an element. As a parameter, you get a pointer to a LVITEMW structure next to the HWND of the ListView, which must be filled in advance.
The structural elements in detail:
Mask:
Specifies which elements are used. A combination of the following flags is possible:
LVIF_IMAGE iImage
LVIF_INDENT iIndent
LVIF_PARAM lParam
LVIF_STATE state
LVIF_TEXT pszText
iItem
Index (0-based) of the item to which the structure relates.
iSubItem
Index (1-based) of the subitem to which the structure relates. 0 if the structure refers to an item instead of a subitem.
pszText
points to a null-terminated string. If the value is LPWSTR_TEXTCALLBACK, it is a callback item. If this changes, pszText must be set to LPSTR_TEXTCALLBACK and the ListView informed by LVM_SETITEMW or LVM_SETITEMTEXT.
pszText must not be set to LPWSTR_TEXTCALLBACK if the ListView has the style LVS_SORTASCENDING or LVS_SORTDESCENDING.
cchTextMax
Size of the buffer when the text is read.
iImage
Index of the icon of this element from the image list.
lParam
32-bit value that is specific to this element.
Actions with elements
LVM_INSERTITEM Insertion of an element
LVM_DELETEITEM Delete an element
LVM_DELETEALLITEMS Delete all elements
LVM_GETITEMW Read properties of the element
LVM_GETITEMTEXT Read text of the element
LVM_SETITEMW change
LVM_SETITEMTEXT Change to the text
Before inserting multiple items, an LVM_SETITEMCOUNT message will be sent to the ListView indicating how many items will ultimately be contained. This allows the ListView to optimize its memory allocation and release. How many elements a ListView contains can be determined with LVM_GETITEMCOUNT.
Editing selected elements
int Pos = -1;
LVITEMW Item;
Pos = ListView_GetNextItem(hwndList, Pos, LVNI_SELECTED);
while (Pos> = 0)
{
Item.iItem = Pos;
Item.iSubItem = 0;
ListView_GetItem(hwndList, & Item);
TuWasMitElement((Element Type * ) Item.lParam);
Pos = ListView_GetNextItem(hwndList, Pos, LVNI_SELECTED);
}
Events
The ListView sends WM_NOTIFY messages to the parent window. The code can take the following values:
Message............ Description
LVN_BEGINDRAG.............Start a drag-and-drop action
LVN_BEGINRDRAG..........Start a drag-and-drop action with the right mouse button
LVN_BEGINLABELEDIT....Start editing a label
LVN_ENDLABELEDIT.......End edit of a label
LVN_DELETEITEM..........Reports that the item is deleted
LVN_DELETEALLITEMS..Reports that all items are deleted
LVN_COLUMNCLICK......Indicates that the user clicked in the header of a report display
LVN_GETDISPINFO.......The control requests information about the presentation from the parent window
LVN_SETDISPINFO.......The information of the parent window for the item must be renewed
LVN_INSERTITEM..........Indicates the insertion of an item
LVN_ITEMCHANGED.....Indicates that an item has been changed
LVN_ITEMCHANGING....Indicates the intended change of an item
LVN_KEYDOWN.............Key was pressed
Editing the labels
The list view must have been created using the LVS_EDITLABELS style. Then a label can already be clicked on and inputs are accepted. However, the input is discarded immediately afterwards. To allow changes in the label, you just need to catch the WM_NOTIFY and return TRUE. In order to access the entered text in between, access is made to the text of the item. The example shows the input in a message box.
case WM_NOTIFY:
switch (((LPNMHDR) lParam) -> code)
{
case LVN_ENDLABELEDIT:
pItem = (NMLVDISPINFO) lParam;
MessageBox (hWnd, pItem-> item.pszText, "entry", MB_OK);
return TRUE;
If editing was aborted, the pszText element will be 0.
If you want to prevent editing, the message LVN_BEGINLABELEDIT is caught and returned TRUE. Here, too, the item can be accessed in the same way via lParam and thus, for example, a certain item group can be excluded.
Click on the column header in the ListView
case WM_NOTIFY:
switch (((LPNMHDR) lParam) -> code)
{
case LVN_COLUMNCLICK:
ColumnNr = ((LPNMLISTVIEW) lParam) -> iSubItem;
.....
Selection Event
The LVN_ITEMACTIVATE event is sent when the user activates an item. As with the other ListView events, it achieves the window function as part of a WM_NOTIFY message.
case WM_NOTIFY:
switch (((LPNMHDR) lParam) -> code)
{
case LVN_ITEMACTIVATE:
HWND hwndFrom = (HWND) ((LPNMHDR) lParam) -> hwndFrom;MarkedItemIndex =
ListView_GetNextItem(hwndFrom, -1, LVNI_SELECTED);
.....
The LVM_GETSELECTEDCOUNT message can be used to determine how many items have been activated. The LVM_GETNEXTITEM message is sent with the LVNI_SELECTED attribute and all items have been edited.
Scenario
In a screen I have 2 managers: 1) menu manager at the top and 2) body manager that has info/button elements. The menu manager does custom drawing so that its menu elements (LabelFields) are properly spaced.
Core Issue - Manager and subfield drawing order
The screen draws fine except when the user preforms an action (clicks a button) that results in an element withing the body manager being added/removed. Once field elements are added/removed from the body, the order in which the menu is drawn gets mixed up.
When the body manager adds or removes a field, instead of the menu manager drawing itself and then its sub elements (label fields), the menu manager begins to draw its sub elements and then itself; thus painting on top of the label fields and making them look like they've disappeared.
Comments
Already tried invalidate and other options -- I've tried to call invalidate, invalidateall, updateDisplay... after adding/removing field elements from body. All without success.
Removing custom sublayout works -- The only way that I can resolve this issue is to remove the menu managers custom sublayout logic. Unfortunately the menu system then draws in a traditional manner and does not provide enough spacing.
Below is the sublayout code for the menu manager, am I missing something here?
public void sublayout(int iWidth, int iHeight)
{
final int iNumFields = getFieldCount();
int maxHeight = 0;
final int segmentWidth = iWidth / iNumFields;
final int segmentWidthHalf = segmentWidth / 2;
for (int i = 0; i < iNumFields; i++)
{
final Item currentField = (Item)this.getField(i);
// 1. Use index to compute bounds of the field
final int xSegmentTrueCenter = segmentWidth * i + segmentWidthHalf;
// 2. center field inbetween bounds using field width (find fill width of text)
final int xFieldStart = xSegmentTrueCenter - currentField.getFont().getAdvance(currentField.getText())/2;
// set up position
setPositionChild(currentField, xFieldStart, getContentTop() + MenuAbstract.PADDING_VERTICAL);
// allow child to draw itself
layoutChild(currentField, iWidth, currentField.getHeight());
// compute max height of the field
//int fieldheight = currentField.getHeight();
maxHeight = currentField.getHeight() > maxHeight
? currentField.getHeight() + 2 * MenuAbstract.PADDING_VERTICAL
: maxHeight;
}
this.setExtent(iWidth, maxHeight);
}
Final Questions
Ultimately I want to keep the custom layout of the menu manager while being allowed to redraw field elements. Here are my final questions:
Have you experienced this before?
Why would the menu manager begin drawing in the wrong order when a field element is added/remove to the screen?
Does the native Manager.sublayout() do something that I'm not to maintain drawing order?
I haven't seen the behavior you describe, but the following line is a little troubling:
// allow child to draw itself
layoutChild(currentField, iWidth, currentField.getHeight());
getHeight() shouldn't return a sensible value until the field has had setExtent called through the layoutChild method. Though I'd expect that it would cause problems in all cases - not sure why this would work the first time around. In your logic I think you can safely just use iHeight instead of currentField.getHeight() in that line. The field will only make itself as big as it needs to be - it won't use all of iHeight unless it's something like a VerticalFieldManager