Adds a label in the 3D View of the name of the Action currently being edited in the Dopesheet.

ShowActionNameIn3dView.py

bl_info = {
    "name": "Show Action Name in 3D View",
    "description": "Adds a label in the 3D View of the name of the Action currently being edited in the Dopesheet.",
    "author": "Ferdinand Joseph Fernandez",
    "version": (1, 0),
    "location": "",
    "support": "TESTING",
    "category": "Animation",
}

import bpy, bgl, blf

def is_in_visible_layer(ob):
    ob_layers = ob.layers
    scene_layers = bpy.context.scene.layers
    
    for layer_index in range(len(ob_layers)):
        if ob_layers[layer_index] == True and scene_layers[layer_index] == True:
            return True
    
    return False

class DrawingClass:    
    def start(self, context):
        self.space = bpy.types.SpaceView3D
        self.area_id = "VIEW_3D"
        self.region_id = "WINDOW"
        self.handle = self.space.draw_handler_add(
                   self.draw_text_callback,(context,),
                   self.region_id, "POST_PIXEL")
        self.area = None
        
        self.dopesheet_area = None
    
    def draw_text_callback(self, context):
        
        text = None
        
        
        # if selected object has an action, use that
        if (bpy.context.active_object is not None and bpy.context.active_object.animation_data is not None and bpy.context.active_object.animation_data.action is not None):
            text = bpy.context.active_object.animation_data.action.name
        
        
        # if dopesheet is open and has an action, use that
        
        if (self.dopesheet_area is None):
            # loop through areas
            # get the dopesheet
            for area in bpy.context.screen.areas:
                if area.type == "DOPESHEET_EDITOR":
                    self.dopesheet_area = area
                    break
                    
        if (self.dopesheet_area is not None):
            action = self.dopesheet_area.spaces[0].action
            if (action is not None):
                text = action.name
        
        
        # if scene has an armature that is visisble in the 3d view and is using an action, use that
        
        for scene_ob in bpy.context.scene.objects:
            if scene_ob.type != 'ARMATURE' or scene_ob.hide == True or is_in_visible_layer(scene_ob) == False:
                continue
            
            if (scene_ob.animation_data is not None and scene_ob.animation_data.action is not None):
                text = scene_ob.animation_data.action.name
                break
        
        if (text is None):
            return
        
        
        # determine text pos and size
        
        font_id = 0  # 0 is default font
        blf.size(font_id, 11, 72)
        #label_size = blf.dimensions(font_id, text)
        
        text_x = 68
        text_y = 25
        #padding = 5
        #text_x = 100
        #if (self.area is not None):
        #    # alight to right edge
        #    text_x = self.area.width - label_size[0] - 15
        #text_y = 27 # above scrollbar
        
        
        # draw the text's bg
        
        #bgl.glPushAttrib(bgl.GL_ENABLE_BIT)
        # glPushAttrib is done to return everything to normal after drawing
        #bgl.glColor4f(0,0,0,0.8)
        #bgl.glEnable(bgl.GL_BLEND)

        #bgl.glBegin(bgl.GL_QUADS)
        
#        bgl.glVertex2f(text_x-padding, text_y-padding)
#        bgl.glVertex2f(text_x-padding, text_y+label_size[1]+padding)
#        bgl.glVertex2f(text_x+label_size[0]+padding, text_y+label_size[1]+padding)
#        bgl.glVertex2f(text_x+label_size[0]+padding, text_y-padding)

#        bgl.glEnd()
#        bgl.glPopAttrib()
        
        
        # draw the text
        
        bgl.glPushAttrib(bgl.GL_COLOR_BUFFER_BIT)
        bgl.glColor4f(0.8,0.8,0.8,1)
        blf.position(font_id, text_x, text_y, 0)
        blf.enable(font_id, blf.SHADOW)
        blf.shadow(font_id, 5, 0, 0, 0, 1)
        blf.draw(font_id, text)
        blf.disable(font_id, blf.SHADOW)
        bgl.glPopAttrib()

    def remove_handle(self):
         self.space.draw_handler_remove(self.handle, self.region_id)

dc = DrawingClass()


def register():
    dc.start(bpy.context)
    
    
def unregister():
    dc.remove_handle()  # will remove the handle and stop drawing
    
    
if __name__ == "__main__":
    register()