Struct CellDataFunc 

pub struct CellDataFunc { /* private fields */ }

A cell data func set on a CellLayout’s CellRenderer.

When implementing CellLayoutImpl::set_cell_data_func, you will need to store these, keyed to the passed CellRenderer, somewhere in your class’s instance data. Whenever your implementation needs to set attribute values on the cell renderers for a particular TreeIter, you should use CellDataFunc::call in order to do so, if there is a CellDataFunc instance present for that cell renderer.

Example

struct MyWidget {
   model: RefCell<TreeModel>,
   items: RefCell<Vec<MyItem>>,
   cells: RefCell<Vec<CellRenderer>>,
   cell_data_funcs: RefCell<HashMap<CellRenderer, CellDataFunc>>,
   // ... other fields
}

impl CellLayoutImpl for MyWidget {
    fn set_cell_data_func(&self, cell: &CellRenderer, cell_data_func: Option<CellDataFunc>) {
        // Store or clear the passed CellDataFunc.
        if let Some(cell_data_func) = cell_data_func {
            self.cell_data_funcs.borrow_mut().insert(cell.clone(), cell_data_func);
        } else {
            self.cell_data_funcs.borrow_mut().remove(cell);
        }
        // Things have changed, so redraw.
        self.redraw();
    }
}

impl MyWidget {
    fn redraw(&self) {
        for item in &*self.items.borrow() {
            let iter: TreeIter = item.iter(&*self.model.borrow());
            for cell in &*self.cells.borrow() {
                if let Some(cell_data_func) = self.cell_data_funcs.borrow().get(cell) {
                    // There's a CellDataFunc for this CellRenderer, so call it so it can set
                    // renderer attributes for the item at this iter.
                    cell_data_func.call(&*self.obj(), cell, &*self.model.borrow(), &iter);
                }
            }
            item.draw(&*self.cells.borrow());
        }
    }
}

Implementations

impl CellDataFunc

pub fn call( &self, cell_layout: &impl IsA<CellLayout>, cell: &impl IsA<CellRenderer>, model: &impl IsA<TreeModel>, iter: &TreeIter, )

Calls the data func on the specified cell renderer, tree model, and iter.

Usually this will set up cell’s attribute values correctly for iter.

Trait Implementations

impl Drop for CellDataFunc

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.