Focusing the graph editor area to a custom [frame, keyframe_value] range

Question

I'm writing to Space types with draw callbacks bgl & blf. The area region.type == 'WINDOW' gives me the height and width correctly re 'UI', 'TOOLS' and 'CHANNELS' regions, but also includes the scrollbars. Writing a 100% width box overwrites the scrollbars that determine what frame and value ranges are displayed.

Is there an API method available to focus in on a custom range, hopefully without needing to use the border select operator:

graph_area = context.screen.areas[4] # area.type = 'GRAPH_EDITOR'
graph_window_region = graph_area.regions[-1] # region.type = 'WINDOW'

c = context.copy()  # copy the context
c['area'] = graph_area
c['region'] = graph_window_region

# call ops with over-ridden context

bpy.ops.graph.view_all(c)
bpy.ops.graph.select_border(c, gesture_mode=3, xmax=lf, ymax=action_max)
bpy.ops.graph.view_selected(c)

The ops above focus the view to varying degrees of success, less so if there are envelope modifiers on the fcurves.

Here is an example of what I want to get to.

ie having the full frame range and the value range in the top half of the region, my soundvis in the lower half.

EDIT

Ok I can fudge the value axis of the preview range by adding a dummy property and keying in bottom left and top right coords, selecting and calling bpy.ops.graph.view_selected(c) as shown below. The issue now is the frames, and looking at the image it occurs to me the preview range is including the handles. More to come.

PS: @CoDEmanX, thanks re scrollbars. apologies for the late edit, happier with the title now, the previous was a bit of a late night afterthought on this. I'm afraid tho you are quite right and there is no way to do this.

Answer 1

Scrollbars aren't exposed to Python, you can't check or change their scroll position in a script.

Answer 2

Ok got this via a workaround

Added a dummy action with 3 keyframes, bottom left, bottom centre, and top right.

def get_view_action(bl, tr):
    '''
    focus the graph editor to the sound fcurves
    bl bottom left (frame, value) 2d coord
    tr top right
    '''
    view_action = bpy.data.actions.get("view_action")

    if view_action is None:
        dp = '["view"]'
        obj["view"] = 0.0
        # create one
        view_action = bpy.data.actions.new("view_action")
        fc = view_action.fcurves.new(dp)
        # add 3 keyframe points
        fc.keyframe_points.add(3)
    else:
        fc = view_action.fcurves[0]

    (a, b, c) = fc.keyframe_points

    a.co = bl
    b.co = (bl[0] + tr[0] / 2.0, bl[1]) 
    c.co = tr

    return view_action

And when needed find your 'GRAPH_EDITOR' area(s)

# obj with action we want to focus in on in graph ed.
action = obj.animation_data.action
dummyaction  = get_view_action((frame_start, min_val), (frame_end, max_val))
# swap in the dummy
obj.animation_data.action = dummyaction
# context override , area is an area of type 'GRAPH_EDITOR'
c = context.copy()
region = area.regions[-1]

c["space_data"] = area.spaces.active
c["area"] = area
c["region"] = region
#bpy.ops.graph.view_selected(c, include_handles=False)
bpy.ops.graph.view_all(c)
# revert the action.
obj.animation_data.action = action

The visualiser height in the view can be determined using

v = graph_editor_window_region.view2d
(m, n) = Vector(v.region_to_view(1,1)) - Vector(v.region_to_view(0,0))
# m is how many pixels wide a frame is in view
# visualiser height from view pixels to keyframe value
kfh = vis_height * n

The dummy action can then be removed. Image below shows the dummy used to focus graph before being removed.