[SOLVED]How to delete an item from the treeview by droping an item to pushbutton or to an group box

[mrjj]

@Ratzz
Hi yes you would still need the DropEvent.

This works with ListWidget with dragDrop mode set to DragOnly.
Since the DropAction is "move", it did remove the item from the list.
Your result may vary.

#ifndef DROPBUTTON_H
#define DROPBUTTON_H

#include <QPushButton>
#include <QDragMoveEvent>

class DropButton : public QPushButton {
  Q_OBJECT
 public:
  explicit  DropButton(QWidget* parent = 0) : QPushButton(parent) {
    setAcceptDrops(true);
  }
 protected:
  void dragEnterEvent(QDragEnterEvent* event) {
    event->acceptProposedAction();
  }

  void dropEvent(QDropEvent* event) {
    event->setDropAction(Qt::MoveAction);
    event->accept();
  }
};

#endif // DROPBUTTON_H

[Ratzz]

@mrjj
I tried this

#include <QDragMoveEvent>
#include <QDropEvent>
protected:
    void dragMoveEvent(QDragMoveEvent *event);
    void dropEvent(QDropEvent *event);

ui->pushButton_DeleteMinorFrame->setAcceptDrops(true);

void Window::dragMoveEvent(QDragMoveEvent *event)
{
    Window *source =qobject_cast<Window *>(event->source());
    if (source && source != this &&
            (event->answerRect().intersects(ui->pushButton_DeleteMinorFrame->geometry())))
    {
        event->acceptProposedAction();
    }
}

void Window::dropEvent(QDropEvent *event)
{
    event->setDropAction(Qt::MoveAction);
    event->accept();
}

But above does not work for me. Where did i miss??
Control does not come to these function dragMoveEvent/dropEvent when i drag and drop

[mrjj]

Hi you have to use the Dropbutton also.

That is why I though using Mainwindow would be easier.

Best way to do that is to use the promote feature.

1. save the code in a file called dropbutton.h
   (just to be safe, also create dropbutton.cpp as empty)
2. right click on your button you want to be a drop button.
   Select "Promote To..."
   In "Promoted classname" type
   DropButton
   (case Matters!)
   in
   header file : type
   dropbutton.h
   Then click "Add" and then Promote.
   Now when you run the program, the normal buttons becomes the DropButton.

[ClapCreative]

Thanks mates

[Ratzz]

@mrjj
Yes, i Tried you code which turns out to be a Dropbutton. How to implement it in my code ?

[mrjj]

@Ratzz
As I wrote in answer ?
Using the promote feature.
Which will runtime replace a normal button with the DropButton.
Or you can new a button you self
Like
Dropbutton *but=Dropbutton (this)
and insert into your window/layout.

[Ratzz]

@mrjj
Yes its working now fine..
I have group box adjacent to treeview. Can i implement the same to groupbox?

[mrjj]

@Ratzz
Super.
Well If you promote the GroupBox, there might be issue with
Parent. I have never tried it.
Try it :)
If it says funny stuff , just demote it to a groupbox again.

Else its pretty much the same, except new filename and new name.

#include <QGroupBox>
#include <QDragMoveEvent>

class DropGroupBox : public QGroupBox {
  Q_OBJECT
 public:
  explicit  DropGroupBox(QWidget* parent = 0) : QGroupBox(parent) {
    setAcceptDrops(true);
  }
 protected:
  void dragEnterEvent(QDragEnterEvent* event) {
    event->acceptProposedAction();
  }

  void dropEvent(QDropEvent* event) {
    event->setDropAction(Qt::MoveAction);
    event->accept();
  }
};

[Ratzz]

@mrjj
i promoted the group using Qpushbutton but not allow me to promote the GroupBox. so i added dropgroupBox.h and promoted it.
But its not working.

[mrjj]

@Ratzz
Hi
Something must gone wrong. maybe.
Tried it here and it does accept drops

https://www.dropbox.com/s/7bkqatzm6vt1kmz/promotedgb.zip?dl=0

[SGaist]

Out of curiosity… Why are you creating so many widgets that should allow to delete items from your view using dnd ? It doesn't feel very intuitive nor following the guidelines of major OSs

[Ratzz]

@mrjj
Yes your code is working . But do not know in my case its not working .
You have used Listwidget and i have used list view . Does it matters??

[Ratzz]

@SGaist
Yes , My treeview is in between listview and groupbox . even if the listview items are dragged to the pushbutton_delete its getting deleted. which in my case should not. what is the best way to do ??

[SGaist]

Implement it in one of the usual ways:

• React to the delete or backspace key
• Have a delete button that will delete the currently selected row/column etc.
• Have a dedicated column with e.g. a QPushButton to delete the row completely.

[Ratzz]

@SGaist
I already have a delete button which deletes entire row.

[Ratzz]

@mrjj
The code you shared is working (group box).

[mrjj]

@Ratzz
Ok. super.

[Ratzz]

@mrjj
But now i can drag items from treeview as well as listview to pushbutton and groupbox. But i do not want the user to allow listview items to dragged to pushbutton/groupbox

[mrjj]

@Ratzz
Hmm maybe you can check with
sender();
in dragEnterEvent
and if its the not a Treeview then reject the drop

like

QTreeView* theone= dynamic_cast<QTreeView*>(sender());
   if( theone!= NULL ) 
   { 
      event->acceptProposedAction();
   }

[Ratzz]

@mrjj
I do not have dragEnterEvent event yet! . we have a custom event using dropMimeData .