Auto-generate mnemonics to activate tools (#300)

debian/changelog

@@ -2,6 +2,7 @@ drawing (1.0.0) unstable; urgency=low
 
   * dynamically change the label of the "options" submenu in the menu-bar, to increase its discoverability
   *
+  * enable tools with "alt+letter" mnemonics
   * artificially limited framerate to avoid overloading the CPU (#162)
   * toggle the menubar with ctrl+f2
   *

src/tools/abstract_tool.py

@@ -37,7 +37,7 @@ def __init__(self, tool_id, label, icon_name, window, **kwargs):
 		# The tool's identity
 		self.id = tool_id
 		self.menu_id = 0
-		self.label = label
+		self.label = self.mnemolabel = label
 		self.icon_name = icon_name
 		# The options it supports
 		self.accept_selection = False
@@ -47,7 +47,6 @@ def __init__(self, tool_id, label, icon_name, window, **kwargs):
 		self.cursor_name = 'cell'
 		self._ongoing_operation = False
 		# Once everything is set, build the UI
-		self.build_row()
 		self.try_build_pane()
 
 	############################################################################
@@ -114,7 +113,7 @@ def adapt_to_window_size(self, available_width):
 		pass
 
 	def add_item_to_menu(self, tools_menu):
-		tools_menu.append(self.label, 'win.active_tool::' + self.id)
+		tools_menu.append(self.mnemolabel, 'win.active_tool::' + self.id)
 
 	def get_options_model(self):
 		"""Returns a Gio.MenuModel corresponding to the tool's options. It'll be
@@ -144,24 +143,25 @@ def build_row(self):
 			relief = Gtk.ReliefStyle.NONE, \
 			draw_indicator = False, \
 			valign = Gtk.Align.CENTER, \
-			tooltip_text = self.label \
+			tooltip_text = self.label, \
 		)
 
 		self.row.set_detailed_action_name('win.active_tool::' + self.id)
-		self.label_widget = Gtk.Label(label=self.label)
+		self._label_widget = Gtk.Label(use_underline=True, label=self.mnemolabel)
 		if self.window.gsettings.get_boolean('big-icons'):
 			size = Gtk.IconSize.LARGE_TOOLBAR
 		else:
 			size = Gtk.IconSize.SMALL_TOOLBAR
 		image = Gtk.Image().new_from_icon_name(self.icon_name, size)
 		box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL, spacing=8)
 		box.add(image)
-		box.add(self.label_widget)
+		box.add(self._label_widget)
 		self.row.add(box)
 		self.row.show_all()
+		return self.row
 
 	def set_show_label(self, label_visible):
-		self.label_widget.set_visible(label_visible)
+		self._label_widget.set_visible(label_visible)
 		if label_visible:
 			self.row.get_children()[0].set_halign(Gtk.Align.START)
 		else:

src/tools/classic_tools/tool_experiment.py

@@ -10,7 +10,6 @@ class ToolExperiment(AbstractClassicTool):
 
 	def __init__(self, window, **kwargs):
 		super().__init__('experiment', _("Experiment"), 'applications-utilities-symbolic', window)
-		self.row.get_style_context().add_class('destructive-action')
 
 		# In order to draw pressure-sensitive lines, the path is collected as
 		# an array whose elements are dicts (keys are 'x', 'y', 'p'). An actual
@@ -57,6 +56,11 @@ def __init__(self, window, **kwargs):
 		self.add_tool_action_enum('experiment_operator', self._operator_label)
 		self.add_tool_action_enum('experiment_mode', self._selected_mode)
 
+	def build_row(self):
+		super().build_row()
+		self.row.get_style_context().add_class('destructive-action')
+		return self.row
+
 	def get_edition_status(self):
 		return "You're not supposed to use this tool (development only)."
 

src/window.py

@@ -204,6 +204,8 @@ def _init_tools(self):
 		# self._load_tool('skew', ToolSkew, disabled_tools, dev)
 		self._load_tool('filters', ToolFilters, disabled_tools, dev)
 
+		self._add_auto_mnemonics()
+
 		# Side pane buttons for tools, and their menubar items if they don't
 		# exist yet (they're defined on the application level)
 		self._build_tool_rows()
@@ -220,6 +222,59 @@ def _init_tools(self):
 		# method, will be called later because it requires an active image,
 		# which doesn't exist yet at this point of the window init process.
 
+	def _add_auto_mnemonics(self):
+		# I don't want useful tools lacking a mnemonic accelerator because a
+		# useless one "stole" its letters, so the mnemonics are decided in the
+		# following order:
+		sorted_tools = [
+			'pencil',
+			'text',
+			'rect_select',
+			'crop',
+			'scale',
+			'rotate',
+			'shape',
+			'filters',
+			'line',
+			'highlight',
+			'arc',
+			'picker',
+			'brush',
+			'free_select',
+			'eraser',
+			'skew',
+			'paint',
+			'color_select',
+			'points',
+			'experiment'
+		]
+		for tool_id in self.tools:
+			if tool_id not in sorted_tools:
+				print("Warning: " + tool_id + "will not have a mnemonic")
+
+		underlined_chars = {}
+		for tool_id in sorted_tools:
+			if tool_id not in self.tools:
+				continue
+			letter_index = 0
+			while(letter_index >= 0):
+				if letter_index == len(self.tools[tool_id].label):
+					letter_index = -1
+					continue
+				ith_char = self.tools[tool_id].label[letter_index]
+				letter_index += 1
+
+				if ith_char.isalpha() \
+				and ith_char.upper() not in underlined_chars.values() \
+				and ith_char.lower() not in underlined_chars.values():
+					underlined_chars[tool_id] = ith_char
+					letter_index = -1
+
+		for tool_id in underlined_chars:
+			c = underlined_chars[tool_id]
+			new_label = self.tools[tool_id].label.replace(c, "_" + c, 1)
+			self.tools[tool_id].mnemolabel = new_label
+
 	def _enable_first_tool(self):
 		"""Near the end of the window initialisation process, this method is
 		called once to make sure all things related to the active tool, mostly
@@ -247,7 +302,7 @@ def _build_tool_rows(self):
 		"""Adds each tool's button to the side pane."""
 		group = None
 		for tool_id in self.tools:
-			row = self.tools[tool_id].row
+			row = self.tools[tool_id].build_row()
 			if group is None:
 				group = row
 			else: