space_view3d_panel_measure.py

            in [op.bl_idname for op in mgr_ops]):
            layout.operator("view3d.activate_measure_panel",
                        text="Activate")

    def draw(self, context):
        layout = self.layout
        sce = context.scene
        mode = context.mode

        # Get a single selected object (or nothing).
        obj = getSingleObject()

        drawTansformButtons = 1

        if mode == 'EDIT_MESH':
            obj = context.active_object

            row = layout.row()
            row.operator("view3d.reenter_editmode",
                text="Update selection")
#               @todo
#                description="The calculated values can" \
#                    " not be updated in mesh edit mode" \
#                    " automatically. Press this button" \
#                    " to do this manually, after you changed" \
#                    " the selection")

            if obj and obj.type == 'MESH' and obj.data:
                # "Note: a Mesh will return the selection state of the mesh
                # when EditMode was last exited. A Python script operating
                # in EditMode must exit EditMode before getting the current
                # selection state of the mesh."
                # http://www.blender.org/documentation/249PythonDoc/
                # /Mesh.MVert-class.html#sel
                # We can only provide this by existing & re-entering EditMode.
                # @todo: Better way to do this?

                # Get mesh data from Object.
                mesh = obj.data

                # Get transformation matrix from object.
                ob_mat = obj.matrix_world
                # Also make an inversed copy! of the matrix.
                ob_mat_inv = ob_mat.copy()
                Matrix.invert(ob_mat_inv)

                # Get the selected vertices.
                # @todo: Better (more efficient) way to do this?
                verts_selected = [v for v in mesh.vertices if v.select == 1]

                if len(verts_selected) == 0:
                    # Nothing selected.
                    # We measure the distance from...
                    # local  ... the object center to the 3D cursor.
                    # global ... the origin to the 3D cursor.
                    layout.label(text="Distance")

                    box = layout.box()
                    row = box.row()
                    row.prop(sce, "measure_panel_dist")

                    row = box.row()
                    row.label(text="", icon='CURSOR')
                    row.label(text="", icon='ARROW_LEFTRIGHT')
                    if measureLocal(sce):
                        row.label(text="Obj. Center")
                    else:
                        row.label(text="Origin [0,0,0]")

                    layout.prop(sce, "measure_panel_draw")

                elif len(verts_selected) == 1:
                    # One vertex selected.
                    # We measure the distance from the
                    # selected vertex object to the 3D cursor.
                    layout.label(text="Distance")

                    box = layout.box()
                    row = box.row()
                    row.prop(sce, "measure_panel_dist")

                    row = box.row()
                    row.label(text="", icon='CURSOR')
                    row.label(text="", icon='ARROW_LEFTRIGHT')
                    row.label(text="", icon='VERTEXSEL')

                    layout.prop(sce, "measure_panel_draw")

                elif len(verts_selected) == 2:
                    # Two vertices selected.
                    # We measure the distance between the
                    # two selected vertices.
                    layout.label(text="Distance")

                    box = layout.box()
                    row = box.row()
                    row.prop(sce, "measure_panel_dist")

                    row = box.row()
                    row.label(text="", icon='VERTEXSEL')
                    row.label(text="", icon='ARROW_LEFTRIGHT')
                    row.label(text="", icon='VERTEXSEL')

                    layout.prop(sce, "measure_panel_draw")

                edges_selected = [ed for ed in mesh.edges if ed.select == 1]
                if len(edges_selected) >= 1:
                    row = layout.row()
                    row.prop(sce, "measure_panel_calc_edge_length",
                        text="Edge Length (selected edges)")

                    if sce.measure_panel_calc_edge_length:
                        if sce.measure_panel_edge_length >= 0:
                            box = layout.box()
                            row = box.row()
                            row.label(
                                text=str(len(edges_selected)),
                                icon='EDGESEL')

                            row = box.row()
                            row.label(text="Length")
                            row.prop(sce, "measure_panel_edge_length")

                if len(verts_selected) > 2:
                    row = layout.row()
                    row.prop(sce, "measure_panel_calc_area",
                        text="Surface area (selected faces)")

                    if sce.measure_panel_calc_area:
                        # Get selected faces
                        # @todo: Better (more efficient) way to do this?
                        polys_selected = [p for p in mesh.polygons
                            if p.select == 1]

                        if len(polys_selected) > 0:
                            if sce.measure_panel_area1 >= 0:
                                box = layout.box()
                                row = box.row()
                                row.label(
                                    text=str(len(polys_selected)),
                                    icon='FACESEL')

                                row = box.row()
                                row.label(text="Area")
                                row.prop(sce, "measure_panel_area1")

                                row = box.row()
                                row.label(text="Normal")
                                row = box.row()
                                row.prop(sce, "measure_panel_normal1")

                        else:
                            row = layout.row()
                            row.label(text="Selection not supported",
                                icon='INFO')

                if drawTansformButtons:
                    row = layout.row()
                    row.prop(sce,
                        "measure_panel_transform",
                        expand=True)

        elif mode == 'OBJECT':
            # We are working in object mode.

            mesh_objects = [o for o in context.selected_objects
                        if o.type == 'MESH']

            if len(context.selected_objects) > 2:
                # We have more that 2 objects selected...

                # EDGES
                row = layout.row()
                row.prop(sce, "measure_panel_calc_edge_length",
                    text="Edge Length")

                if sce.measure_panel_calc_edge_length:
                    if len(mesh_objects) > 0:
                        box = layout.box()

                        row = box.row()
                        row.label(text="Total edge length")
                        row.prop(sce, "measure_panel_edge_length")

                # AREA
                row = layout.row()
                row.prop(sce, "measure_panel_calc_area",
                        text="Surface area")

                if sce.measure_panel_calc_area:
                    if len(mesh_objects) > 0:
                        # ... and at least one of them is a mesh.

                        # Calculate and display surface area of the objects.
                        # @todo: Convert to scene units! We do not have a
                        # FloatProperty field here for automatic conversion.

                        row = layout.row()
                        row.label(text="Multiple objects not yet supported",
                            icon='INFO')
                        row = layout.row()
                        row.label(text="(= More than two meshes)",
                            icon='INFO')
# @todo Make this work again.
#                        for o in mesh_objects:
#                            area = objectSurfaceArea(o, False,
#                                measureGlobal(sce))
#                            if area >= 0:
#                                row = layout.row()
#                                row.label(text=o.name, icon='OBJECT_DATA')
#                                row.label(text=str(round(area, PRECISION))
#                                    + " BU^2")

            elif len(context.selected_objects) == 2:
                # 2 objects selected.
                # We measure the distance between the 2 selected objects.
                layout.label(text="Distance")

                obj1, obj2 = context.selected_objects

                box = layout.box()
                row = box.row()
                row.prop(sce, "measure_panel_dist")

                row = box.row()
                row.label(text="", icon='OBJECT_DATA')
                row.prop(obj1, "name", text="")

                row.label(text="", icon='ARROW_LEFTRIGHT')

                row.label(text="", icon='OBJECT_DATA')
                row.prop(obj2, "name", text="")

                layout.prop(sce, "measure_panel_draw")

                # EDGES
                row = layout.row()
                row.prop(sce, "measure_panel_calc_edge_length",
                    text="Edge Length")

                if sce.measure_panel_calc_edge_length:
                    if sce.measure_panel_edge_length >= 0:
                        if len(mesh_objects) > 0:
                            box = layout.box()

                            row = box.row()
                            row.label(text="Total edge length")
                            row.prop(sce, "measure_panel_edge_length")

                # AREA

                row = layout.row()
                row.prop(sce, "measure_panel_calc_area",
                    text="Surface area")

                if sce.measure_panel_calc_area:
                    # Display surface area of the objects.
                    if (sce.measure_panel_area1 >= 0
                    or sce.measure_panel_area2 >= 0):
                        if sce.measure_panel_area1 >= 0:
                            box = layout.box()
                            row = box.row()
                            row.label(text=obj1.name, icon='OBJECT_DATA')

                            row = box.row()
                            row.label(text="Area")
                            row.prop(sce, "measure_panel_area1")

                            row = box.row()
                            row.label(text="Normal")
                            row = box.row()
                            row.prop(sce, "measure_panel_normal1")

                        if sce.measure_panel_area2 >= 0:
                            box = layout.box()
                            row = box.row()
                            row.label(text=obj2.name, icon='OBJECT_DATA')

                            row = box.row()
                            row.label(text="Area")
                            row.prop(sce, "measure_panel_area2")

                            row = box.row()
                            row.label(text="Normal")
                            row = box.row()
                            row.prop(sce, "measure_panel_normal2")

                # VOL
                row = layout.row()
                row.prop(sce, "measure_panel_calc_volume",
                    text="Volume")

                if sce.measure_panel_calc_volume:
                    # Display volume of the objects.
                    if sce.measure_panel_volume1 >= -2:
                        box = layout.box()
                        row = box.row()
                        row.label(text=obj1.name, icon='OBJECT_DATA')

                        if sce.measure_panel_volume1 >= 0:
                            row = box.row()
                            row.label(text="Volume")
                            row.prop(sce, "measure_panel_volume1")
                        elif sce.measure_panel_volume1 >= -1:
                            row = box.row()
                            row.label(text="Mesh is non-manifold!",
                                icon='INFO')
                        else:  # -2
                            row = box.row()
                            row.label(text="Mesh has n-gons (faces with " \
                                "more than 4 edges)!",
                                icon='INFO')

                    if sce.measure_panel_volume2 >= -2:
                        box = layout.box()
                        row = box.row()
                        row.label(text=obj2.name, icon='OBJECT_DATA')

                        if sce.measure_panel_volume2 >= 0:
                            row = box.row()
                            row.label(text="Volume")
                            row.prop(sce, "measure_panel_volume2")
                        elif sce.measure_panel_volume2 >= -1:
                            row = box.row()
                            row.label(text="Mesh is non-manifold!",
                                icon='INFO')
                        else:  # -2
                            row = box.row()
                            row.label(text="Mesh has n-gons (faces with " \
                                "more than 4 edges)!",
                                icon='INFO')

            elif obj:
                # One object selected.
                # We measure the distance from the object to the 3D cursor.
                layout.label(text="Distance")

                box = layout.box()
                row = box.row()
                row.prop(sce, "measure_panel_dist")

                row = box.row()
                row.label(text="", icon='CURSOR')

                row.label(text="", icon='ARROW_LEFTRIGHT')

                row.label(text="", icon='OBJECT_DATA')
                row.prop(obj, "name", text="")

                layout.prop(sce, "measure_panel_draw")

                # EDGES
                row = layout.row()
                row.prop(sce, "measure_panel_calc_edge_length",
                    text="Edge Length")

                if sce.measure_panel_calc_edge_length:
                    if sce.measure_panel_edge_length >= 0:
                        if len(mesh_objects) > 0:
                            box = layout.box()

                            row = box.row()
                            row.label(text="Total edge length")
                            row.prop(sce, "measure_panel_edge_length")

                # AREA
                row = layout.row()
                row.prop(sce, "measure_panel_calc_area",
                    text="Surface area")

                if sce.measure_panel_calc_area:
                    # Display surface area of the object.

                    if sce.measure_panel_area1 >= 0.0:
                        box = layout.box()
                        row = box.row()
                        row.label(text=obj.name, icon='OBJECT_DATA')

                        row = box.row()
                        row.label(text="Area")
                        row.prop(sce, "measure_panel_area1")

                        row = box.row()
                        row.label(text="Normal")
                        row = box.row()
                        row.prop(sce, "measure_panel_normal1")

                # VOL
                row = layout.row()
                row.prop(sce, "measure_panel_calc_volume",
                    text="Volume")

                if sce.measure_panel_calc_volume:
                    # Display volume of the objects.
                    if sce.measure_panel_volume1 >= -2:
                        box = layout.box()
                        row = box.row()
                        row.label(text=obj.name, icon='OBJECT_DATA')

                        if sce.measure_panel_volume1 >= 0:
                            row = box.row()
                            row.label(text="Volume")
                            row.prop(sce, "measure_panel_volume1")
                        elif sce.measure_panel_volume1 >= -1:
                            row = box.row()
                            row.label(text="Mesh is non-manifold!",
                                icon='INFO')
                        else:  # -2
                            row = box.row()
                            row.label(text="Mesh has n-gons (faces with " \
                                "more than 4 edges)!",
                                icon='INFO')

            elif not context.selected_objects:
                # Nothing selected.
                # We measure the distance from the origin to the 3D cursor.
                layout.label(text="Distance")

                box = layout.box()
                row = box.row()
                row.prop(sce, "measure_panel_dist")

                row = box.row()
                row.label(text="", icon='CURSOR')
                row.label(text="", icon='ARROW_LEFTRIGHT')
                row.label(text="Origin [0,0,0]")

                layout.prop(sce, "measure_panel_draw")

            else:
                row = layout.row()
                row.label(text="Selection not supported",
                    icon='INFO')

            if drawTansformButtons:
                row = layout.row()
                row.prop(sce,
                    "measure_panel_transform",
                    expand=True)


def register():
    bpy.utils.register_module(__name__)

    bpy.app.handlers.scene_update_post.append(scene_update)

    # Define a temporary attribute for the distance value
    bpy.types.Scene.measure_panel_dist = bpy.props.FloatProperty(
        name="Distance",
        precision=PRECISION,
        unit="LENGTH")
    bpy.types.Scene.measure_panel_edge_length = bpy.props.FloatProperty(
        name="",
        precision=PRECISION,
        unit="LENGTH")
    bpy.types.Scene.measure_panel_area1 = bpy.props.FloatProperty(
        name="",
        precision=PRECISION,
        unit="AREA")
    bpy.types.Scene.measure_panel_area2 = bpy.props.FloatProperty(
        name="",
        precision=PRECISION,
        unit="AREA")
    bpy.types.Scene.measure_panel_normal1 = bpy.props.FloatVectorProperty(
        name="",
        precision=PRECISION,
        subtype="XYZ")
    bpy.types.Scene.measure_panel_normal2 = bpy.props.FloatVectorProperty(
        name="",
        precision=PRECISION,
        subtype="XYZ")
    bpy.types.Scene.measure_panel_volume1 = bpy.props.FloatProperty(
        name="",
        precision=PRECISION,
        unit="VOLUME")
    bpy.types.Scene.measure_panel_volume2 = bpy.props.FloatProperty(
        name="",
        precision=PRECISION,
        unit="VOLUME")

    TRANSFORM = [
        ("measure_global", "Global",
         "Calculate values in global space"),
        ("measure_local", "Local",
         "Calculate values inside the local object space")]

    # Define dropdown for the global/local setting
    bpy.types.Scene.measure_panel_transform = bpy.props.EnumProperty(
        name="Space",
        description="Choose in which space you want to measure",
        items=TRANSFORM,
        default='measure_global')

    # Define property for the draw setting.
    bpy.types.Scene.measure_panel_draw = bpy.props.BoolProperty(
        name="Draw distance",
        description="Draw distances in 3D View",
        default=1)

    bpy.types.Scene.measure_panel_calc_edge_length = bpy.props.BoolProperty(
        description="Calculate total length of (selected) edges",
        default=0)

    # Define property for the calc-area setting.
    # @todo prevent double calculations for each refresh automatically?
    bpy.types.Scene.measure_panel_calc_area = bpy.props.BoolProperty(
        description="Calculate mesh surface area (heavy CPU "
                    "usage on bigger meshes)",
        default=0)

    # Define property for the calc-volume setting.
    bpy.types.Scene.measure_panel_calc_volume = bpy.props.BoolProperty(
        description="Calculate mesh volume (heavy CPU "
                    "usage on bigger meshes)",
        default=0)

     # Define dropdown for the global/local setting
    bpy.types.Scene.measure_panel_update = bpy.props.BoolProperty(
        description="Update CPU heavy calculations",
        default=0)

    pass


def unregister():
    bpy.utils.unregister_module(__name__)

    bpy.app.handlers.scene_update_post.remove(scene_update)

    # Remove properties.
    del bpy.types.Scene.measure_panel_dist
    del bpy.types.Scene.measure_panel_edge_length
    del bpy.types.Scene.measure_panel_area1
    del bpy.types.Scene.measure_panel_area2
    del bpy.types.Scene.measure_panel_normal1
    del bpy.types.Scene.measure_panel_normal2
    del bpy.types.Scene.measure_panel_volume1
    del bpy.types.Scene.measure_panel_volume2
    del bpy.types.Scene.measure_panel_transform
    del bpy.types.Scene.measure_panel_draw
    del bpy.types.Scene.measure_panel_calc_edge_length
    del bpy.types.Scene.measure_panel_calc_area
    del bpy.types.Scene.measure_panel_calc_volume
    del bpy.types.Scene.measure_panel_update

    pass

if __name__ == "__main__":
    register()