This should be pretty easy but I'm having a heck of a time doing it. Basically I want to move a row in my wxListCtrl up or down. I posted this to wxwidgets forum and got the following code.
m_list->Freeze();
wxListItem item;
item.SetId(item_id); // the one which is selected
m_list->GetItem(item); // Retrieve the item
m_list->DeleteItem(item_id); // Remove it
item.SetId(item_id - 1); // Move it up
m_list->SetItem(item); // Apply it's new pos in the list
m_list->Thaw();
which doesn't work. The element is deleted but not moved up (I guess the setitem line is not working). Then I thought to just switch the text and the image but I can't even get the text from the row reliably. I have
int index = m_right->GetNextItem(-1, wxLIST_NEXT_ALL, wxLIST_STATE_SELECTED);
wxString label = m_right->GetItemText(index);
if(index == 0)
return;
wxListItem item;
item.SetId(index);
bool success = m_right->GetItem(item);
wxString text = item.GetText();
but text is blank even though there is text and the index is correct. So, I'm stuck not even being able to do the most basic task. Anybody know how to do this? The code runs in a button callback (the user presses a little up arrow and my code executes to try to move it). I'm using 2.9.1 on windows.
I made it work like this with wxWidgets 2.9.3 :
void FileSelectionPanel::OnMoveUp( wxCommandEvent& WXUNUSED(evt) )
{
int idx = _listCtrl->GetNextItem( -1, wxLIST_NEXT_ALL, wxLIST_STATE_SELECTED );
if( idx == 0) idx = _listCtrl->GetNextItem( 0, wxLIST_NEXT_ALL, wxLIST_STATE_SELECTED );
_listCtrl->Freeze();
while( idx > -1 ) {
wxListItem item;
item.SetId(idx); _listCtrl->GetItem(item);
item.SetId(idx-1); _listCtrl->InsertItem(item);
_listCtrl->SetItemData( idx-1, _listCtrl->GetItemData( idx+1 ));
for( int i = 0; i < _listCtrl->GetColumnCount(); i++ ) {
_listCtrl->SetItem( idx-1, i, _listCtrl->GetItemText( idx+1, i ));
}
_listCtrl->DeleteItem( idx + 1 );
idx = _listCtrl->GetNextItem( idx-1, wxLIST_NEXT_ALL, wxLIST_STATE_SELECTED );
}
_listCtrl->Thaw();
}
The thing I noticed it that wxListItem is more of a convenience struct, for storing state of the view and help pass values into the wxListCtrl "nicely". It is in no way bound to what is actually inside of the wxListCtrl.
Hope this still helps anyone !
Even there is already an answer that is checked. I have the same problem here, but my list is unordered. By looking into wxWidgets' code I found out there is another important information inside the wxListItem object - the mask. I got my reordering to work correctly by setting the mask value to -1, which means that all data shall be copied. This includes the item text as well as other information, like the item data (which was important in my case).
wxListItem item;
item.SetId(item_id); // set needed id
item.SetMask(-1); // set needed data
m_list->GetItem(item); // actually retrieve the item
m_list->DeleteItem(item_id); // remove old copy
item.SetId(item_id - 1); // move item up
m_list->InsertItem(item); // insert copy of item
I also had to use "InsertItem" instead of "SetItem". Otherwise, there was no new item inserted, but an existing one overwritten (see also tomcat31's answer).
Is the list ordered? if it is auto ordering it may be ignoring the order you are trying to apply.
From recollection the internal order was not necessarily sequential, you might have to get the index of the previous item and go one before it.
Related
I struggle a bit with deleting struct from my TArray of structs.My struct contains AudioComponent and float.I was using Array.RemoveAt(index), but what i got from this was only removing half of my struct, which is AudioComponent.
Why is that? My function Removing elements looks like this:
void RemoveArrayElement( UAudioComponent AudioComponent )
{
for( int i=0; i<Array.Num(); i++ )
{
if( AudioComponent == Array[i].AudioComponent )
{
Array.RemoveAt( i );
}
}
}
What i want to achieve is completely deleting index, AudioComponent with it's float.
There are few issues with your code. As others mentioned in comments, you should use pointers. And if I'm not mistaken, you aren't allowed to use construction like this:
UPROPERTY()
TArray<UAudioComponent> invalidArray;
You should use UPROPERTY macro, otherwise your properties could and probably will be garbage collected. UPROPERTY wiki.
Next thing is that you are changing array over which you are iterating. I wrote few approaches, let's look at them:
void RemoveArrayElement(UAudioComponent* AudioComponent)
{
TArray<UAudioComponent*> audioArray; // array will be initialized somewhere else, this is for demo purpose.
// you always should check your pointers for validity
if (!AudioComponent || !AudioComponent->IsValidLowLevel() || AudioComponent->IsPendingKill())
return;
// Correct approach 1 (multiple):
TQueue<UAudioComponent*> toDelete;
for (int i = 0; i < audioArray.Num(); i++)
{
auto item = audioArray[i];
if (AudioComponent == item || true) // we simulate another condition for multiselect
{
toDelete.Enqueue(item);
}
}
// better approach for iteration:
for (auto item : audioArray)
if (item == AudioComponent || true) // we simulate another condition for multiselect
toDelete.Enqueue(item);
// finalize deletion in approach 1
UAudioComponent* deleteItem;
while (toDelete.Dequeue(deleteItem))
audioArray.Remove(deleteItem);
// almost correct approach 2 (single) :
UAudioComponent* foundItem;
for (auto item : audioArray)
if (item == AudioComponent)
{
foundItem = item;
break; // we can skip rest - but we must be sure, that items were added to collection using AddUnique(...)
}
if (foundItem)
audioArray.Remove(foundItem);
// correct and the best - approach 3 (single)
audioArray.Remove(AudioComponent);
}
First keep in mind that comparing two objects does not necessarily lead to the expected result of equality. Using the == operator means executing a function (bool operator==(L, R);) that specifies what should happen. So if you did not overload the == operator then you don't know what using it would result to unless you look at the source code where it's defined. Since you want to remove the exact audio component and not an instance of it that looks the same, you want to use pointers in your array. That also helps performance since your are not copying the whole component when calling RemoveArrayElement(...); but a single pointer. Also when there are two identical audio components stored in the array and they are at index a and a+1, then removing the audio component at index a the next iteration would skip your second audio component since all upper indexes are decremented by one.
I'm working on a scheduling program, and inside the dataGridView, we have a few ComboBox Columns that are populated by 3 entries upon creation, but I wanted to be able to add more as the user creates them, but I have no idea how you would access the combobox data. Any help is appreciated!
// this is initialized in a separate part.
/* System::Windows::Forms::DataGridView^ dataGridView;*/
System::Windows::Forms::DataGridViewComboBoxColumn^ newCol =
(gcnew System::Windows::Forms::DataGridViewComboBoxColumn());
dataGridView->Columns->AddRange(gcnew cli::array< System::Windows::Forms::DataGridViewComboBoxColumn^ >(1) {newCol});
// add the choices to the boxes.
newCol->Items->AddRange("User inputted stuff", "More stuff", "Add New...");
Solution
If you have access to the data from the user entry and you know the column index for the DataGridViewComboBoxColumn, you should be able to just do the following wherever needed:
DataGridViewComboBoxColumn^ comboboxColumn = dataGridView->Columns[the_combobox_column_index];
if (comboboxColumn != nullptr)
{
comboboxColumn->Items->Add("the new user entry");
}
Comments Response
how could you change the selected index of that combobox (the one that
the edit was triggered on)? [...] we want it so that when the new item
is added the selected index is set to that new item).
Couple of ways come to mind.
Add a single line within the if-statement of the above code. This will set the default displayed value for each DataGridViewComboBoxCell in the DataGridViewComboBoxColumn.
if (comboboxColumn != nullptr)
{
comboboxColumn->Items->Add("the new user entry");
comboboxColumn->DefaultCellStyle->NullValue = "the new user entry";
}
Pros: Clean, efficient. Previous user-selected values are left intact. The cell's FormattedValue will display the new user value by default if no other selection has been made.
Cons: Doesn't actually set a cell's selected value, so Value will return null on cells not explicitly user-selected.
Actually set the value of certain cells (based on your criteria) to the user-added value.
if (comboboxColumn != nullptr)
{
comboboxColumn->Items->Add("the new user entry");
for (int i = 0; i < dataGridView->Rows->Count; i++)
{
DataGridViewComboBoxCell^ cell = dataGridView->Rows[i]->Cells[the_combobox_column_index];
if ( cell != nullptr /* and your conditions are met */ )
{
cell->Value = "the new user entry";
}
}
}
Pros: The Value of targeted cells is actually set to the new user value.
Cons: Logic deciding which cells should be affected is more complicated.
I am working with list control in MFC. I have written code to insert elements into list control present in a dialog box as follows:
int nIndex = 0;
for (int count = 0; count < arrResults.GetSize(); count++)
{
nIndex = m_cListCtrl.InsertItem(count, _T(arrResults[count].ElementAt(0)));
m_cListCtrl.SetItemText(nIndex, 1, _T(arrResults[count].ElementAt(1)));
}
However, when I try to retrieve data from m_cListCtrl, it always returns blank. Also, the GetItemCount() method also returns 0 items. Any suggestions are appreciated.
Following is the data retrieve code that I have written:
arrResults.SetSize(1);
arrResults[0].Add("Header1");
arrResults[0].Add("Header2");
TestDialog testDlg;
testDlg.FillControlList(arrResults); // This function has above code to add data to control list
EXPECT_EQ("Header1", queryDlg.m_cListCtrl.GetItemText(0, 0));
EXPECT_EQ("Header2", queryDlg.m_cListCtrl.GetItemText(0, 1));
The GetItemText function is returning blank string.
When you call FillControlList(), you are using testDlg object. But when you call GetItemText() you're using queryDlg object. You have inserted the items in one dialog and you're trying to get data from different object. Please check with that.
I want to delete selected row of list control in MFC.
I have created a Delete Button, So If any row (it could be one or more than one row) is/are selected and I press delete button that/those rows should be deleted.
If lets say there are 100 rows and I select rows from 50-60, all the rows in this range should be deleted and rest of rows should have indexes from 1 to 90. means indexing should be proper after deletion also.
Adapted from this MSDN article:
UINT i, uSelectedCount = m_myListCtrl.GetSelectedCount();
int nItem;
if (uSelectedCount > 0)
for (i=0; i < uSelectedCount; i++)
{ nItem = m_myListCtrl.GetNextItem(-1, LVNI_SELECTED);
ASSERT(nItem != -1);
m_myListCtrl.DeleteItem(nItem);
}
When deleting a multiple selection having several items I prefer to do it like this:
int nItem = -1;
while ((nItem = m_list.GetNextItem(nItem, LVNI_SELECTED)) != -1)
{
if (m_list.DeleteItem(nItem))
nItem--;
}
Notice the important nItem--; line
UPDATE
I had to give up from this approach as the ItemData of an element gots fucked up. If I remove the nth element then the n+1 element will be my new nth. That element has a completely screwed up Itemdata.
UPDATE 2
I also tried with
int nItem = -1;
while ((nItem = m_list.GetNextItem(-1, LVNI_SELECTED)) != -1)
{
m_list.DeleteItem(nItem);
}
This approach also has the problem of screwing the Itemdata I reported before.
The following approach worked perfecly for me:
std::stack< int > items;
int nItem = -1;
while ((nItem = myListCtrl.GetNextItem(nItem, LVNI_SELECTED)) != -1)
{
items.push(nItem);
}
bool removed = false;
while (!items.empty())
{
nItem = items.top();
if (myListCtrl.DeleItem(nItem))
removed = true;
items.pop();
}
if (removed)
// update some application state;
Explanation:
When you remove things from the end to the start, you do not have to worry about the validity of positions. As the CListCtrl does not provide a GetPrevItem or any other way to get items in the reverse order, you need to store them in a collection where you can have that reverse order.
The most practical way to do it is to use a stack. Due to the way it works, you will put things in there in the normal order, and when you retrieve things they are automatically in reverse order.
I was coding with 2 CStringList objects. Each has its own data, for eg one has name and other the phoneno, and both are in sync, i.e, if there is a phoneno there is a name and viceversa.
Now, i have 2 combobox in which i show the names and the respective phonenos. The name combobox is sorted, hence the sync between the two goes for a toss. hence for sorting i did the following:
int aComboElementNo = myNameComboBox.GetCount();
if( aComboElementNo >= 1 )
{
for( int aIndex = 0; aIndex < aComboElementNo; aIndex++ )
{
CString aTempStr;
// Getting the string in the combobox
myNameComboBox.GetLBText( aIndex, aTempStr );
// Getting the position where the name is present in the list
POSITION aPos = aNameList.Find( aTempStr );
// setting the appropriate phoneno in the 2nd combobox
myPhoneComboBox.AddString( aPhoneList.GetAt( aPos ) );
}
}
When i executed this i got the names in the myPhoneComboBox rather than the phonenos.
Now i have 2 qns:
how come i get the name present in namelist when i am accessing the phonelist? isn't it a breach, as i am able to access some other variables data using some other variable.
how to sort the 2nd list.
I Hope U are using CStringArray and not CStringList.
You need to use FindIndex rather than Find since Find will return OBJECT Pos rather than the Index count....
and to get the element with array use simply [] the operator.
If You still want to use CStringList then through Iterator Find the Index Count of the first match of string in one List and Use FindIndex of that IndexCount to get the postition object for the secondlist to use GetAt to the second list.
Why do you have 2 separate lists? Why not one CTypedPtrArray of structures holding both the name and the phone nb?
That is a crazzy, forgive me, stupid way to find names. It assumes the names are unique. God help me, I've had to deal with these things, name fields should never be viewed as unique, its bloody dangerious. Just ask my dad Baash05 Sr.
I'd assume there's an ID or some data set as the app adds to the combo box. Please use that in your map. My guess is the programmer set the data to either the ID of the name, or a pointer to the object that contained the name. (person object/business object/student object...).
If the code that adds the names didn't add a way to tell the difference between George Forman and any of his kids, then make an argument to the boss, that it's implementation should be changed, because by god it should be!
int aComboElementNo = myNameComboBox.GetCount();
for( int aIndex = 0; aIndex < aComboElementNo; aIndex++ )
{
int nameLocal = myNameComboBox.GetItemData( aIndex);
myPhoneComboBox.InsertString(aIndex, aPhoneList[namelocal] );
}