The icons toolbar and View menu functions

In this iteration, we will add the following functionalities to the text editor:

• Showing shortcut icons on the toolbar
• Displaying line numbers
• Highlighting the current line
• Changing the color theme of the editor

Let's start with a simple task first. In this step, we will add shortcut icons to the toolbar, as shown in the following screenshot:

You may recall that we have already created a frame to hold these icons. Let's add these icons now.

While adding these icons, we have followed a convention. The icons have been named exactly the same as the corresponding function that handles them. Following this convention has enabled us to loop through a list, simultaneously apply the icon image to each button, and add the command callback from within the loop. All the icons have been placed in the icons folder.

The following code adds icons to the toolbar (2.10.py):

icons = ('new_file', 'open_file', 'save', 'cut', 'copy', 'paste', 'undo', 'redo', 'find_text')
for i, icon in enumerate(icons):
   tool_bar_icon = PhotoImage(file='icons/{}.gif'.format(icon))
   cmd = eval(icon)
   tool_bar = Button(shortcut_bar, image=tool_bar_icon, command=cmd)
   tool_bar.image = tool_bar_icon
   tool_bar.pack(side='left')

The following is a description of the preceding code:

• We have already created a shortcut bar in the first iteration. Now, we will simply add buttons with images in the frame.
• We create a list of icons, taking care to name them exactly the same as the name of the icons.
• We then loop through the list by creating a Button widget, adding an image to the button, and adding the respective callback command.
• Before adding the callback command, we have to convert the string to an equivalent expression by using the eval command. If we do not apply eval, it cannot be applied as an expression to the callback command.

Thus, we've added shortcut icons to the shortcut bar. Now, if you run the code (refer to 2.10.py in the code bundle), it should show all of the shortcut icons. Moreover, as we have linked each button to its callback, all of these shortcut icons should work.