class PaletteView(GridView)
A
PaletteView is a specialised subclass of GridView designed for
implementing tool palettes and other such components. Instead of row
and column numbers, the cells in a PaletteView are identified by a
single integer index, called an item number, with items being numbered from left to right, top to bottom.
The PaletteView also has a notion of one or more items being selected, and provides support for highlighting selected items in a variety of ways.
PaletteView inherits from ScrollableView and can therefore be made scrollable if needed, although it does not show any scroll bars by default.
The extent of a PaletteView is managed through the num_items, items_per_row and cell_size properties. The num_rows and num_columns properties inherited from GridView, and the extent property inherited from ScrollableView, should not be changed directly.
Constructor
- PaletteView(num_items, items_per_row, cell_size)
- Creates a palette view with the specified initial property values.
Properties
- num_items
- Total number of items in the palette. The items will be laid out with items_per_row items in each row, using as many rows as necessary. If num_items is not an even multiple of items_per_row, some cells in the last row will be left empty.
- items_per_row
- The number of items in each row of the palette's extent.
- highlight_style
- The style in which to highlight selected items. Possible values are:
- 'fill' - the cell is filled with the highlight_color before calling draw_item().
- 'frame' - a rectangle is drawn around the cell as specified by highlight_color and highlight_thickness before calling draw_item().
- '' or None - no automatic highlighting is performed.
- highlight_color
- Color to use for highlighting of selected items.
- highlight_thickness
- When using the 'frame' highlight style, the pen width to use for drawing the highlight rectangle.
Abstract Methods
- draw_item(canvas, item_number, item_rect)
- Should draw the specified item in the given rectangle. Any automatic highlighting specified by the highlight_style property has already been applied.
- click_item(item_number, event)
- Called when a mouse_down event occurs in an item.
- item_is_selected(item_number)
- Should return true if the indicated item is to be regarded as selected.
- draw_item_and_highlight(canvas, item_number, item_rect, highlight)
- This method can optionally be overridden instead of draw_item()
to gain more control over how items are highlighted. Your
implementation should draw the specified item, and apply highlighting
if highlight is true. If you override this method, draw_item() is not called and no automatic highlighting is performed.
Methods
- item_rect(item_number)
- Returns the rectangle corresponding to the given item number. If the item number is out of bounds (less than 0 or greater than num_items - 1), returns None.
- item_no_of_cell(row_number, column_number)
- Returns the item number corresponding to the specified cell, or None if the cell does not correspond to a valid item.
- cell_of_item_no(item_number)
- Returns the row and column numbers of the cell corresponding to the given item number. If the item number is out of bounds (less than 0 or greater than num_items - 1), returns None.