Use bitmap icons in place of Unicode icons where possible

src/crystal/browser/__init__.py

@@ -4,6 +4,7 @@
 from crystal.browser.addgroup import AddGroupDialog
 from crystal.browser.addrooturl import AddRootUrlDialog
 from crystal.browser.entitytree import EntityTree, ResourceGroupNode, RootResourceNode
+from crystal.browser.icons import TREE_NODE_ICONS
 from crystal.browser.preferences import PreferencesDialog
 from crystal.browser.tasktree import TaskTree
 from crystal.model import (
@@ -19,6 +20,7 @@
 from crystal.ui.actions import Action
 from crystal.ui.BetterMessageDialog import BetterMessageDialog
 from crystal.ui.log_drawer import LogDrawer
+from crystal.ui.tree import DEFAULT_FOLDER_ICON_SET
 from crystal.util.finderinfo import get_hide_file_extension
 from crystal.util.unicode_labels import decorate_label
 from crystal.util.wx_bind import bind
@@ -195,19 +197,15 @@ def _create_actions(self) -> None:
             wx.AcceleratorEntry(wx.ACCEL_CTRL, ord('R')),
             self._on_add_url,
             enabled=(not self._readonly),
-            button_label=decorate_label(
-                RootResourceNode.ICON,
-                'New &Root URL...',
-                RootResourceNode.ICON_TRUNCATION_FIX))
+            button_bitmap=TREE_NODE_ICONS()['entitytree_root_resource'],
+            button_label='New &Root URL...')
         self._new_group_action = Action(wx.ID_ANY,
             'New &Group...',
             wx.AcceleratorEntry(wx.ACCEL_CTRL, ord('G')),
             self._on_add_group,
             enabled=(not self._readonly),
-            button_label=decorate_label(
-                ResourceGroupNode.ICON,
-                'New &Group...',
-                ResourceGroupNode.ICON_TRUNCATION_FIX))
+            button_bitmap=dict(DEFAULT_FOLDER_ICON_SET())[wx.TreeItemIcon_Normal],
+            button_label='New &Group...')
         self._forget_action = Action(wx.ID_ANY,
             '&Forget',
             wx.AcceleratorEntry(wx.ACCEL_CTRL, wx.WXK_BACK),

src/crystal/browser/icons.py

@@ -80,4 +80,28 @@ def _add_badge_to_background(background: wx.Bitmap, badge: wx.Bitmap) -> wx.Bitm
     return background_plus_badge
 
 
+def add_transparent_left_border(original: wx.Bitmap, thickness: int) -> wx.Bitmap:
+    if thickness == 0:
+        return original
+
+    bordered = wx.Bitmap()
+    success = bordered.Create(
+        original.Width + thickness,
+        original.Height,
+        original.Depth)
+    if not success:
+        raise Exception('Failed to create a wx.Bitmap')
+
+    dc = wx.MemoryDC(bordered)
+    dc.Clear()  # fill bitmap with white
+    dc.DrawBitmap(
+        original,
+        x=thickness,
+        y=0,
+        useMask=True)
+    dc.SelectObject(wx.NullBitmap)  # commit changes to bordered
+    bordered.SetMaskColour(wx.Colour(255, 255, 255))  # replace white with transparent
+    return bordered
+
+
 # ------------------------------------------------------------------------------

src/crystal/ui/actions.py

@@ -1,5 +1,6 @@
+from crystal.browser.icons import add_transparent_left_border
 from crystal.util.wx_bind import bind
-from crystal.util.xos import is_mac_os
+from crystal.util.xos import is_mac_os, is_windows
 from typing import Callable, List, Optional
 import wx
 
@@ -21,12 +22,14 @@ def __init__(self,
             accel: Optional[wx.AcceleratorEntry]=None,
             action_func: Optional[Callable[[wx.CommandEvent], None]]=None,
             enabled: bool=True,
+            button_bitmap: Optional[wx.Bitmap]=None,
             button_label: str=''):
         self._menuitem_id = menuitem_id
         self._label = label
         self._accel = accel
         self._action_func = action_func
         self._enabled = enabled
+        self._button_bitmap = button_bitmap
         self._button_label = button_label
 
         self._menuitems = []  # type: List[wx.MenuItem]
@@ -78,6 +81,16 @@ def create_button(self, *args, **kwargs) -> wx.Button:
             button_label = wx.Control.RemoveMnemonics(button_label)  # reinterpret
 
         button = wx.Button(*args, label=button_label, **kwargs)
+        if self._button_bitmap is not None:
+            button.SetBitmap(add_transparent_left_border(
+                self._button_bitmap,
+                # Alter left margin for bitmap to be reasonable on Windows.
+                # Initially it is 0.
+                8+6 if is_windows() else 0
+            ))
+            if is_windows():
+                # Decrease bitmap-to-text spacing on Windows to be reasonable
+                button.SetBitmapMargins((-6, 0))
         # (NOTE: Do NOT set accelerator for the button because it does not
         #        work on consistently on macOS. Any action added as a button
         #        should also be added as a menuitem too, and we CAN set an

src/crystal/ui/tree.py

@@ -28,7 +28,7 @@
 _DEFAULT_TREE_ICON_SIZE = (16,16)
 
 _DEFAULT_FOLDER_ICON_SET_CACHED = None
-def _DEFAULT_FOLDER_ICON_SET() -> IconSet:
+def DEFAULT_FOLDER_ICON_SET() -> IconSet:
     global _DEFAULT_FOLDER_ICON_SET_CACHED  # necessary to write to a module global
     if not _DEFAULT_FOLDER_ICON_SET_CACHED:
         _DEFAULT_FOLDER_ICON_SET_CACHED = (
@@ -258,7 +258,7 @@ def _set_icon_set(self,
             effective_value = (
                 value
                 if value is not None else (
-                    _DEFAULT_FOLDER_ICON_SET()
+                    DEFAULT_FOLDER_ICON_SET()
                     if self.expandable 
                     else _DEFAULT_FILE_ICON_SET()
                 )