Description
live.observer is used to listen to changes in the values of properties of Live objects. This object works in conjunction with the live.path object, which sends id nn messages into the right inlet of live.observer.
After an object id and property is specified, its value is sent out the left outlet. From this moment on, the value is sent on each change of the property ('notification') as well as in response to bang messages.
The left outlet is reserved for value messages, all other output is sent to the right outlet.
Not all properties can be observed, please consult the Live Object Model to see which can. Also, it is not possible to modify the live set from a notification, i.e. while you are receiving a value message spontaneously sent by a live.observer 's outlet.
Besides properties, it is also possible to observer children of Live objects. Their values are object ids or lists of them.
Note: The Live API runs in the main thread in Live, and that all messages to and from the API are automatically deferred.
Examples
Arguments
Attributes
Common Box Attributes
annotation [symbol]
Sets the text that will be displayed in the Clue window when the user moves the mouse over the object.
background [int] (default: 0)
Adds or removes the object from the patcher's background layer. background 1 adds the object to the background layer, background 0 removes it. Objects in the background layer are shown behind all objects in the default foreground layer.
color [4 floats]
Sets the color for the object box outline.
fontface [int]
Sets the type style used by the object. The options are:
plain
bold
italic
bold italic
Possible values:
0 = 'regular'
1 = 'bold'
2 = 'italic'
3 = 'bold italic'
fontname [symbol]
Sets the object's font.
fontsize [float]
Sets the object's font size (in points).
Possible values:
'8'
'9'
'10'
'11'
'12'
'13'
'14'
'16'
'18'
'20'
'24'
'30'
'36'
'48'
'64'
'72'
hidden [int] (default: 0)
Toggles whether an object is hidden when the patcher is locked.
hint [symbol]
Sets the text that will be displayed in as a pop-up hint when the user moves the mouse over the object in a locked patcher.
ignoreclick [int] (default: 0)
Toggles whether an object ignores mouse clicks in a locked patcher.
patching_rect [4 floats] (default: 0. 0. 100. 0.)
Sets the position and size of the object in the patcher window.
position [2 floats]
Sets the object's x and y position in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its size unchanged.
presentation [int] (default: 0)
Sets whether an object belongs to the patcher's presentation.
presentation_rect [4 floats] (default: 0. 0. 0. 0.)
Sets the x and y position and width and height of the object in the patcher's presentation, leaving its patching position unchanged.
rect [4 floats]
Sets the x and y position and width and height of the object in both patching and presentation modes (if the object belongs to its patcher's presentation).
size [2 floats]
Sets the object's width and height in both patching and presentation modes (if the object belongs to its patcher's presentation), leaving its position unchanged.
textcolor [float]
Sets the color for the object's text in RGBA format.
textjustification [int]
Text Justification
Possible values:
0 = 'left'
1 = 'center'
2 = 'right'
varname [symbol]
Sets the patcher's scripting name, which can be used to address the object by name in pattr, scripting messages to thispatcher, and the js object.
Inlets
Left inlet
Right inlet
id 0 means no object, i.e. all messages to the left inlet are ignored, which is also the initial state.
Outlets
Left outlet
Right outlet
Messages
property
Arguments
property the name of a property of the current object
Operation:
Selects the property to be observed. Outputs the current value to the left outlet if a proper Live object is selected.
Remark:
Not all properties can be observed.
The types of the properties are given in the Live Object Model.
| Outlet | Output | Example |
|---|---|---|
| left | value | 3.1415926 |
property
Arguments
child the name of a child of the current object
Operation:
Selects the child id to be observed. Outputs the id (or "id 0") to the left outlet if the selected Live object has such a child.
Remark:
Not all children can be observed.
| Outlet | Output | Example |
|---|---|---|
| left | id nn | id 17 |
property
Arguments
child the name of a child list of the current object
Operation:
Selects the child list to be observed. Outputs the id list (or nothing) to the left outlet if the selected Live object has such a list child.
Remark:
Not all child lists can be observed.
| Outlet | Output | Example |
|---|---|---|
| left | id nn ... id mm | id 4 id 5 |
getproperty
Sends the name of the selected property (or child resp. list-child) out the right outlet.
| Outlet | Output | Example |
|---|---|---|
| right | property property or property child | property name or property selected_track |
gettype
Sends the type of currently observed property or child to the right outlet. The types of the properties and children are given in the Live Object Model.
For list-children it just sends type tuple, w/o further type information.
| Outlet | Output | Example |
|---|---|---|
| right | type property-type or type object-type | type int or type Track |
getid
Sends the id of the currently observed Live object to the right outlet.
| Outlet | Output | Example |
|---|---|---|
| right | id nn | id 20 |
bang
Sends current value of selected property of current object to the left outlet. Does nothing if no property or no Live object is selected or if they don't match.
| Outlet | Output | Example |
|---|---|---|
| left | value | Drums |
id nn
Sets the current object. The message has the same effect if sent to both the right or the left inlet. For clarity it is suggested to always use the right inlet to supply the object id.
- no output -
Inspector
Persistence
The live.observer object has a special entry in its inspector labelled "Use Persistent Mapping". This setting, when enabled, causes the id associated with the object to persist when the Live document is saved and restored, and when the Max Device is moved between the Live application and the Max editor, or within the Live Set. Beginning in Live 8.2.2, Live API ids remain persistent between launches of Live, which in conjunction with the Persistence feature of live.object, live.observer and live.remote~, makes it possible to create simpler devices which retain their association with elements in the Live user interface.
See Also
| Name | Description |
|---|---|
| Max For Live | Max For Live |
| Live API Overview | Live API Overview |
| Live Object Model | LOM - The Live Object Model |
| live.path | Navigate to objects in the Live application |
| live.object | Perform operations on Live objects |
| live.remote~ | Realtime control of device parameters |
| Using the Live API | Creating Devices that use the Live API |
| The LiveAPI JavaScript Object (jsliveapi) | The LiveAPI Object |