Manual python parsing of an .atom file and extracting attribute information

preview_atom_parser.py

from maya import cmds


class ReturnCode:
    anim_layer_found = "anim_layer_found"


def preview_frame_from_atom(atom_path, preview_first_frame=True):
    """
    Manual parse through the .atom file and figure out what a frame looks like

    preview_first_frame: True for the first frame, False for the last frame

    ###################################
    # Example .atom file content
    #
    # keys legend:
    #       index 0: frame
    #       index 1: value

    dagNode {
      anim translate.translateX translateX 0;
      animData {
        keys {
          12 0 auto auto 1 0 0;
        }
    }
    ###################################
    """

    anim_layers_found = False

    with open(atom_path, "r") as fp:
        next_block_contains_key_data = False

        current_ctrl = ""
        current_attr = ""

        pose_data = {}

        previous_line = ""
        for line in fp.readlines():

            if line.startswith("animLayers {"):
                anim_layers_found = True
                break

            if next_block_contains_key_data:

                # if True, grab the first key found in key block
                if preview_first_frame:
                    key_value = line.lstrip().split()[1]
                    pose_data[current_ctrl][current_attr] = float(key_value)
                    next_block_contains_key_data = False

                # otherwise, keep going until we reach the end, then grab the last key data from block
                elif "}" in line:
                    key_value = previous_line.lstrip().split()[1]
                    pose_data[current_ctrl][current_attr] = float(key_value)
                    next_block_contains_key_data = False

            if "anim " in line:
                current_attr = line.lstrip().split()[2]

            if "dagNode {" in previous_line:
                current_ctrl = line.lstrip().split()[0]
                pose_data[current_ctrl] = {}

            if "keys {" in line:
                next_block_contains_key_data = True

            previous_line = line

    if anim_layers_found:
        return ReturnCode.anim_layer_found

    for ctrl, attr_data in pose_data.items():
        for attr_name, attr_val in attr_data.items():
            full_attr = "{}.{}".format(ctrl, attr_name)
            if not cmds.objExists(full_attr):
                cmds.warning("Attribute not found: {}".format(full_attr))
                continue
            cmds.setAttr(full_attr, attr_val)

##################################################
# Example Window hooked up to above function

import pymel.core as pm 

class ExamplePreviewAtomWindow(object):
    def __init__(self):
        
        
        # Make a new window
        win_title = "Example Preview Atom Window"
        win_title_safe = win_title.replace(" ", "_")
        if pm.window(win_title_safe, q=True, exists=True):
            pm.deleteUI(win_title_safe)
            
        window = pm.window(win_title_safe, title=win_title, toolbox=True, backgroundColor=(0.200, 0.300, 0.30))
        window.show()
        
        with pm.verticalLayout() as main_layout:
            self.root_folder_grp = pm.folderButtonGrp(changeCommand=self.update_file_list)
            self.preview_first_frame = pm.checkBox("Preview First Frame", value=True)
            self.atom_list = pm.textScrollList(selectCommand=self.run_preview_on_selected_atom)
            
            main_layout.redistribute(1, 1, 6)
            
    def run_preview_on_selected_atom(self):
        selected_atom_name = self.atom_list.getSelectItem()[0]
        atom_path = os.path.join(self.root_folder_grp.getText(), selected_atom_name)
        preview_frame_from_atom(atom_path, self.preview_first_frame.getValue())
    
    def update_file_list(self, *args):
        self.atom_list.removeAll()
        
        for file_name in os.listdir(self.root_folder_grp.getText()):
            if ".atom" not in file_name.lower():
                continue
                
            self.atom_list.append(file_name)

if __name__ == "__main__":
    win = ExamplePreviewAtomWindow()