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--- graphic:python:blender [2023/11/15 02:13] – [File related Operation] ying
+++ graphic:python:blender [2024/02/01 09:13] – [Blender UI code] ying
@@ Line 38: / Line 38: @@
     if each in bpy.data.objects.keys():
         bpy.data.objects.remove(bpy.data.objects[each], do_unlink=True)
+</code>
+===== cmd related operation =====
+  * send blender file and python script to blender process with parameter <code python>
+# blender use empty scene to load task script with parameter after --, as (blender file, blender preview path, resolution)
+app_path = bpy.app.binary_path
+task_path = os.path.join( os.path.dirname(__file__), 'process', 'task_make_preview.py' )
+info=subprocess.Popen(f'"{app_path}" --python "{task_path}" -- "{file_path}" "{blend_preview_dir}" 512 512',stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+out, err = info.communicate()
+</code>
+  * task script reading parameter inside blender <code python>
+# task script
+import sys
+import bpy
+argv = sys.argv
+argv = argv[argv.index("--") + 1:]  # get all args after "--"
+print(argv)  # --> ['example', 'args', '123']
 </code>
@@ Line 375: / Line 393: @@
 ref:
   * https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Python_API/Addons
+  * https://developer.blender.org/docs/release_notes/2.80/python_api/addons/
   * https://s-nako.work/2020/12/blender-addon-naming-rules/
+  * https://b3d.interplanety.org/en/class-naming-conventions-in-blender-2-8-python-api/
-  * Class name convention is: UPPER_CASE_{SEPARATOR}_mixed_case
+  * **Class name convention**: UPPER_CASE_{SEPARATOR}_mixed_case
-    * Header : _HT_
+    * UPPER_CASE: normally the ADDON_NAME, or a Unique ID_WORD that make it not crashing into other existing class names
-    * Menu : _MT_
+    * {SEPARATOR}
-    * Operator : _OT_
+      * Header : _HT_
-    * Panel : _PT_
+      * Menu : _MT_
-    * UIList : _UL_
+      * Operator : _OT_
-  * like  [A-Z][A-Z0-9_]*_MT_[A-Za-z0-9_]+
+      * Panel : _PT_
-  * if not follow above: you get warning "doesn't contain '_PT_' with prefix & suffix"
+      * UIList : _UL_
+    * mixed_case
+      * _CheckSelection (this more like standard python PEP class naming)
+      * _Check_Selection
+      * _check_selection
+    * like  [A-Z][A-Z0-9_]*_MT_[A-Za-z0-9_]+
+    * if not follow above: you get warning "doesn't contain '_PT_' with prefix & suffix"
+  * **operator ID name convention** (feel like a username for your operator inside blender )
+    * category_name.operator_task_like_name
+      * custom.addon_name_task_name (snake_case like PEP function)
+    * For headers, menus and panels, the bl_idname is expected to match the class name
+      * class: ADDON_NAME_OT_check_selection
+      * bl_idname: addon_name.check_selection
+  * **other same as PEP**
+    * obj = "BigBox"
+    * obj_max_count = 2
+    * def function_name(arg_name)
+    * class ClassName()
+Example of class name, balancing between Python PEP
+  * example addon, <code python>
+class BUILDMAKER_OT_CreateAsset(bpy.types.Operator):
+    bl_idname = "custom.buildmaker_create_asset"
+class CreateAsset(bpy.types.Operator):
+    bl_idname = "BUILDMAKER_OT_CreateAsset"
+class BUILDMAKER_OT_createAsset(bpy.types.Operator):
+# 2.8x onwards, property
+class MyOperator(bpy.types.Operator):
+    value: IntProperty()
+class ToolProperties(bpy.types.PropertyGroup):
+    commandLineMode: bpy.props.BoolProperty(
+        name = "Command line mode",
+        description = "The option specifies if the addon is used in the command line mode",
+        default = False
+    )
+class ToolProps(bpy.types.PropertyGroup):
+    email : StringProperty(
+        name="email",
+        description="User email",
+        default=""
+    )
+class TOOL_PROPS(bpy.types.PropertyGroup):
+    lon: FloatProperty()
+    lat: FloatProperty()
+class BUILDMAKER_PG_color(PropertyGroup):
+    color: FloatVectorProperty(subtype='COLOR', min=0, max=1, update=updColor, size=4)
+</code>
 ===== common blender api commands =====
@@ Line 508: / Line 575: @@
 **UI**
   * bpy.types.Panel
+    * the panel display order is determined by the order bpy.utils.register_class processes
   * bpy.types.UIList
   * bpy.types.Operator
@@ Line 566: / Line 634: @@
 ...
 layout.template_list(type_name, list_id, ptr, propname, active, rows, maxrows, ..) # a list widget
+</code>
+  * long label solution and auto wrap <code python>
+import bpy
+import textwrap
+long_text = """
+        a long text  long text  long text
+        b test
+        c long text  long text  long text  long text  long text  long
+        d text  long text  long text  long text """
+def get_max_label_width():
+    # Get the 3D View area
+    for area in bpy.context.screen.areas:
+        if area.type == 'VIEW_3D':
+            break
+    # Calculate the width of the panel
+    panel_width = 280 # default value
+    for region in area.regions:
+        if region.type == 'UI':
+            panel_width = region.width
+            return panel_width
+            break
+    # Calculate the maximum width of the label
+    uifontscale = 9 * context.preferences.view.ui_scale
+    max_label_width = int(panel_width // uifontscale)
+    return max_label_width
+def create_long_label(layout, long_text, icon='',indent=''):
+    max_label_width = get_max_label_width()
+    first_icon_line_done = False
+    rest_line_indent = indent
+    if icon == '':
+        first_icon_line_done = True
+        rest_line_indent = ''
+    # Split the text into lines and format each line
+    for line in long_text.splitlines():
+        # Remove leading and trailing whitespace
+        line = line.strip()
+        # Split the line into chunks that fit within the maximum label width
+        for chunk in textwrap.wrap(line, width=max_label_width):
+            if not first_icon_line_done:
+                layout.label(text=chunk, icon=icon)
+                first_icon_line_done = True
+            else:
+                layout.label(text=rest_line_indent+chunk)
+class MyPanel(bpy.types.Panel):
+    bl_idname = "OBJECT_PT_my_panel"
+    bl_label = "My Panel"
+    bl_space_type = "VIEW_3D"
+    bl_region_type = "UI"
+    def draw(self, context):
+        layout = self.layout
+        create_long_label(layout, long_text, "KEYTYPE_JITTER_VEC", '    ')
+# Register the panel
+bpy.utils.register_class(MyPanel)
 </code>
 ===== Blender preference =====
@@ Line 584: / Line 712: @@
 bpy.context.preferences.addons[__name__]
 bpy.context.preferences.addons[AddonName].preferences.attributeA
+</code>
+===== 3rd party library =====
+  * use PIL image and blender image <code python>
+# ref: https://blender.stackexchange.com/questions/270924/how-to-open-blenders-image-using-pillow
+# ref: https://stackoverflow.com/questions/21233946/pil-image-save-function-fails-in-blender-python
+import bpy
+import os
+import subprocess
+import sys
+import io
+import struct
+import numpy as np
+try:
+    from PIL import Image
+except:
+    python_exe = os.path.join(sys.prefix, 'bin', 'python.exe')
+    subprocess.call([python_exe, '-m', 'ensurepip'])
+    subprocess.call([python_exe, '-m', 'pip', 'install', '--upgrade', 'pip'])
+    subprocess.call([python_exe, '-m', 'pip', 'install', '--upgrade', 'pillow'])
+def pil_to_image(pil_image, name='NewImage'):
+    width, height = pil_image.width, pil_image.height
+    normalized = 1.0 / 255.0
+    bpy_image = bpy.data.images.new(name, width=width, height=height)
+    bpy_image.pixels[:] = (np.asarray(pil_image.convert('RGBA'),dtype=np.float32) * normalized).ravel()
+    return bpy_image
+def image_to_pil(bpy_image):
+    img = bpy_image
+    pixels = [int(px * 255) for px in bpy_image.pixels[:]]
+    bytes = struct.pack("%sB" % len(pixels), *pixels)
+    pil_image = Image.frombytes('RGBA', (bpy_image.size[0], bpy_image.size[1]), bytes)
+    return pil_image
+im = image_to_pil(bpy.data.images["test"])
+im = im.transpose(Image.FLIP_LEFT_RIGHT).rotate(45)
+pil_to_image(im)
+</code>
+  * alternative <code python>
+bl_info = {
+    "name": "My Test Addon",
+    "category": "Object"}
+def register():
+    import pip
+    pip.main(['install', 'pillow'])
+    from PIL import Image
+def unregister():
+    print("Goodbye World")
 </code>