UI: Add a custom text editor preference

Add a user preference to set up a custom text editor for editing text
files with the "Edit Source" action in the UI context menu.

- An operator TEXT_OT_jump_to_file_at_point has been added.
- A custom editor can be set in the user preferences.
- A preset has been included for "Visual Studio Code".
- When the editor is not set, use Blender's internal editor.

Ref !108299.

scripts/startup/bl_operators/__init__.py

@@ -28,6 +28,7 @@ _modules = [
     "screen_play_rendered_anim",
     "sequencer",
     "spreadsheet",
+    "text",
     "userpref",
     "uvcalc_follow_active",
     "uvcalc_lightmap",

scripts/startup/bl_operators/presets.py

@@ -413,6 +413,24 @@ class AddPresetHairDynamics(AddPresetBase, Operator):
     ]
 
 
+class AddPresetTextEditor(AddPresetBase, Operator):
+    """Add or remove a Text Editor Preset"""
+    bl_idname = "text_editor.preset_add"
+    bl_label = "Add Text Editor Preset"
+    preset_menu = "USERPREF_PT_text_editor_presets"
+
+    preset_defines = [
+        "filepaths = bpy.context.preferences.filepaths"
+    ]
+
+    preset_values = [
+        "filepaths.text_editor",
+        "filepaths.text_editor_args"
+    ]
+
+    preset_subdir = "text_editor"
+
+
 class AddPresetTrackingCamera(AddPresetBase, Operator):
     """Add or remove a Tracking Camera Intrinsics Preset"""
     bl_idname = "clip.camera_preset_add"
@@ -692,6 +710,7 @@ classes = (
     AddPresetOperator,
     AddPresetRender,
     AddPresetCameraSafeAreas,
+    AddPresetTextEditor,
     AddPresetTrackingCamera,
     AddPresetTrackingSettings,
     AddPresetTrackingTrackColor,

scripts/startup/bl_operators/text.py

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+from bpy.types import Operator
+from bpy.props import (
+    IntProperty,
+    StringProperty,
+)
+
+
+class TEXT_OT_jump_to_file_at_point(Operator):
+    bl_idname = "text.jump_to_file_at_point"
+    bl_label = "Open Text File at point"
+    bl_description = "Edit text file in external text editor"
+
+    filepath: StringProperty(name="filepath")
+    line: IntProperty(name="line")
+    column: IntProperty(name="column")
+
+    def execute(self, context):
+        import shlex
+        import subprocess
+        from string import Template
+
+        if not self.properties.is_property_set("filepath"):
+            text = context.space_data.text
+            if not text:
+                return {'CANCELLED'}
+            self.filepath = text.filepath
+            self.line = text.current_line_index
+            self.column = text.current_character
+
+        text_editor = context.preferences.filepaths.text_editor
+        text_editor_args = context.preferences.filepaths.text_editor_args
+
+        if not text_editor_args:
+            self.report(
+                {'ERROR_INVALID_INPUT'},
+                "Provide text editor argument format in File Paths/Applications Preferences, "
+                "see input field tool-tip for more information.",
+            )
+            return {'CANCELLED'}
+
+        if "$filepath" not in text_editor_args:
+            self.report({'ERROR_INVALID_INPUT'}, "Text Editor Args Format must contain $filepath")
+            return {'CANCELLED'}
+
+        args = [text_editor]
+        template_vars = {
+            "filepath": self.filepath,
+            "line": self.line + 1,
+            "column": self.column + 1,
+            "line0": self.line,
+            "column0": self.column,
+        }
+
+        try:
+            args.extend([Template(arg).substitute(**template_vars) for arg in shlex.split(text_editor_args)])
+        except Exception as ex:
+            self.report({'ERROR'}, "Exception parsing template: %r" % ex)
+            return {'CANCELLED'}
+
+        try:
+            # With `check=True` if `process.returncode != 0` an exception will be raised.
+            subprocess.run(args, check=True)
+        except Exception as ex:
+            self.report({'ERROR'}, "Exception running external editor: %r" % ex)
+            return {'CANCELLED'}
+
+        return {'FINISHED'}
+
+
+classes = (
+    TEXT_OT_jump_to_file_at_point,
+)

scripts/startup/bl_ui/space_text.py

@@ -256,7 +256,13 @@ class TEXT_MT_text(Menu):
 
         if text:
             layout.separator()
-            layout.operator("text.reload")
+            row = layout.row()
+            row.operator("text.reload")
+            row.enabled = not text.is_in_memory
+
+            row = layout.row()
+            op = row.operator("text.jump_to_file_at_point", text="Edit Externally")
+            row.enabled = (not text.is_in_memory and context.preferences.filepaths.text_editor != "")
 
             layout.separator()
             layout.operator("text.save", icon='FILE_TICK')

scripts/startup/bl_ui/space_userpref.py

@@ -10,6 +10,7 @@ from bpy.app.translations import (
     pgettext_iface as iface_,
     pgettext_tip as tip_,
 )
+from bl_ui.utils import PresetPanel
 
 
 # -----------------------------------------------------------------------------
@@ -1399,6 +1400,13 @@ class USERPREF_PT_file_paths_render(FilePathsPanel, Panel):
         col.prop(paths, "render_cache_directory", text="Render Cache")
 
 
+class USERPREF_PT_text_editor_presets(PresetPanel, Panel):
+    bl_label = "Text Editor Presets"
+    preset_subdir = "text_editor"
+    preset_operator = "script.execute_preset"
+    preset_add_operator = "text_editor.preset_add"
+
+
 class USERPREF_PT_file_paths_applications(FilePathsPanel, Panel):
     bl_label = "Applications"
 
@@ -1416,6 +1424,25 @@ class USERPREF_PT_file_paths_applications(FilePathsPanel, Panel):
             col.prop(paths, "animation_player", text="Player")
 
 
+class USERPREF_PT_text_editor(FilePathsPanel, Panel):
+    bl_label = "Text Editor"
+    bl_parent_id = "USERPREF_PT_file_paths_applications"
+
+    def draw_header_preset(self, _context):
+        USERPREF_PT_text_editor_presets.draw_panel_header(self.layout)
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+
+        paths = context.preferences.filepaths
+
+        col = layout.column()
+        col.prop(paths, "text_editor", text="Program")
+        col.prop(paths, "text_editor_args", text="Arguments")
+
+
 class USERPREF_PT_file_paths_development(FilePathsPanel, Panel):
     bl_label = "Development"
 
@@ -2510,6 +2537,8 @@ classes = (
     USERPREF_PT_file_paths_script_directories,
     USERPREF_PT_file_paths_render,
     USERPREF_PT_file_paths_applications,
+    USERPREF_PT_text_editor,
+    USERPREF_PT_text_editor_presets,
     USERPREF_PT_file_paths_development,
     USERPREF_PT_file_paths_asset_libraries,