Global event handlers
In the AGS game there is a number of events, like starting the game, or pressing the key, that may be handled in script by adding a function with predefined name. These are called "global event handlers". If you add ones to your script, they will be called automatically whenever corresponding event occurs. All of these are optional, and may be omited if you don't need them.
You may you add multiple functions of the same kind to multiple script modules, in which case they will be called in the order of modules in your game project. It's possible to stop propagating the event (skip remaining modules) by using ClaimEvent
function (refer to its article for explanation).
Some of these functions may also be added to the room scripts. These are: on_event
, on_key_press
, on_mouse_click
, on_text_input
, repeatedly_execute_always
, late_repeatedly_execute_always
.
Some functions will only work in the room script: on_call
.
NOTE: for historical reasons, function repeatedly_execute
does not work in the room script, but there's a corresponding room event that may be linked to a custom function in the editor.
dialog_request
(int parameter) dialog_request
Called when a dialog script line "run-script" is processed. PARAMETER is the value of the number following the "run-script" on that line of the dialog script.
game_start
() game_start
Called at the start of the game, before the first room is loaded. You would typically use this to set up the initial positions of characters, and to modify initial visibility of GUIs.
Note: When this function is called it is too early to run animations or do anything else which relies on a room being loaded
interface_click
(int interface, int button) interface_click
Called when the player clicks on a button on a GUI which has its action set as "Run script". INTERFACE is the number of the GUI which they clicked on. BUTTON is the object number of the button within this GUI.
on_event
(EventType event, int data) on_event
Called whenever certain game events occur. The value of DATA depends on which event has occurred. The possible values of event are:
eEventEnterRoomBeforeFadein
called just before the room's 'Enter Before Fade-in' event occurs
DATA = new room number
eEventEnterRoomAfterFadein
called just before the room's 'Enter After Fade-in' event occurs
DATA = room number
eEventLeaveRoom
called just after the room's 'Player Leaves Room' event occurs, before the fade-out
DATA = room number they are leaving
eEventLeaveRoomAfterFadeout
called when leaving a room, right after fade-out, but while room is still in memory
DATA = room number they are leaving
eEventGotScore
called whenever the player's score changes
DATA = number of points they've received
eEventGUIMouseDown
called when a mouse button is pressed down over a GUI
DATA = GUI number
eEventGUIMouseUp
called when a mouse button is released over a GUI
DATA = GUI number
eEventAddInventory
called when the player has just added an inventory item
DATA = inventory item number that was added
eEventLoseInventory
called when the player has just lost an inventory item
DATA = inventory item number that was lost
eEventRestoreGame
called after a saved game has been restored
DATA = save slot number
eEventGameSaved
called after a game was saved
DATA = save slot number
For example:
function on_event(int event, int data)
{
if (event == eEventEnterRoomBeforeFadein)
{
// do something on each room enter, before screen fades in
}
else if (event == eEventRestoreGame)
{
// do something each time right after a save was restored
}
}
Compatibility:
eEventEnterRoomAfterFadein
event type is only supported since AGS 3.6.0.eEventLeaveRoomAfterFadeout
event type is only supported since AGS 3.6.1.eEventGameSaved
event type is only supported since AGS 3.6.1.
on_key_press
(eKeyCode keycode, optional int mod) on_key_press
Called whenever a key is pressed on the keyboard. keycode
holds the value of the key, while mod
holds a combination of modifiers pressed alongside with that key. A list of these values is available here.
The mod
argument is optional and may be omited. The mod
contains set of flags, and is slightly more complicated than keycode: as you should not use regular comparison (==
, !=
) with it, but a bitwise operator (&
):
// these two conditions check that ctrl was pressed (these commands are equivalent)
if (mod & eKeyModCtrl)
if (mod & eKeyModCtrl != 0)
// these two conditions check that ctrl was NOT pressed (again, two variants of the same check)
if (!(mod & eKeyModCtrl))
if (mod & eKeyModCtrl == 0)
The on_key_press
function can also be defined in individual room scripts. This allows the room script to intercept a key-press first, and then decide whether to pass it on to the global script or not. See the ClaimEvent
function for more details.
Starting with version 3.6.0 AGS supports two "key handling" modes: a new-style and old-style (backwards compatible). This mode is selected in the General Settings with "Use old-style key handling" option in the "Backwards compatibility" group.
New key mode:
- all keys are passed into the
on_key_press
function as-is, one by one: for example, if you press Ctrl + Z, then you get twoon_key_press
calls, one witheKeyCtrlLeft
and another witheKeyZ
argument.
Old (classic) key mode:
- lone mod keys (Ctrl, Alt, Shift) are not passed into the
on_key_press
; you may only test if these are pressed using IsKeyPressed. - alphabet keys + ctrl combinations are merged into one key code for the
on_key_press
callback: e.g.eKeyCodeCtrlA
and similar key codes.
Compatibility: The mod
argument is only supported since AGS 3.6.0.
on_mouse_click
(MouseButton button) on_mouse_click
Called when the player clicks a mouse button. BUTTON is either eMouseLeft
, eMouseRight
, or eMouseMiddle
, depending on which button was clicked. The mouse.x
and mouse.y
global variables contain the mouse's position.
If 'Handle inventory clicks in script' is enabled in the game options, this function can also be called with eMouseLeftInv
, eMouseMiddleInv
or eMouseRightInv
, which indicate a left, middle or right click on an inventory item, respectively.
If 'Enable mouse wheel support' is enabled, this function can also be called with eMouseWheelNorth or eMouseWheelSouth, which indicate the user moving the mouse wheel north or south, respectively.
The on_mouse_click
function can also be defined in individual room scripts. This allows the room script to intercept a mouse-click first, and then decide whether to pass it on to the global script or not. See the ClaimEvent
function for more details.
on_text_input
(int ch) on_text_input
Called when the player's key presses form a printable character. The difference between this and on_key_press
is that not every key corresponds to the printable char, and some chars may be created by pressing multiple keys (which also depends on the current system language).
The ch
argument contains a unicode character code, and may be used with the String functions.
For example:
.Text = MyLabel.Text.AppendChar(ch); MyLabel
will append the new printed character to a label's text.
IMPORTANT: this function only works when your game uses "new-style key handling mode". This mode is selected in the General Settings with "Use old-style key handling" option in the "Backwards compatibility" group.
Compatibility: supported since AGS 3.6.0.
repeatedly_execute
() repeatedly_execute
Called every game cycle (normally 40 times per second). Additional information is available here.
repeatedly_execute_always
() repeatedly_execute_always
Called every game cycle, even when a blocking routine (e.g speech or cutscene) is in progress. You cannot call any blocking functions from this event handler. repeatedly_execute_always
is called before the game entities (characters, rooms, etc) get updated. Additional information is available here.
late_repeatedly_execute_always
() late_repeatedly_execute_always
Called every game cycle, even when a blocking routine (e.g. speech or cutscene) is in progress. You cannot call any blocking functions from this event handler. late_repeatedly_execute_always
is called after the game entities (characters, rooms, etc) have been updated, but before the game screen is redrawn.
unhandled_event
(int what, int type) unhandled_event
Called when an event occurs, but no corresponding event handler has been configured. This is typically used to display a default "I can't do that" type response in-order to avoid having to add unique messages for all in-game interactions. The values of WHAT and TYPE tell you what the player did. The possible values are listed below:
WHAT | TYPE | Description |
---|---|---|
1 | 1 | Look at hotspot |
1 | 2 | Interact with hotspot |
1 | 3 | Use inventory on hotspot |
1 | 4 | Talk to hotspot |
1 | 7 | Pick up hotspot |
1 | 8 | Cursor Mode 8 on hotspot |
1 | 9 | Cursor Mode 9 on hotspot |
2 | 0 | Look at object |
2 | 1 | Interact with object |
2 | 2 | Talk to object |
2 | 3 | Use inventory on object |
2 | 5 | Pick up object |
2 | 6 | Cursor Mode 8 on object |
2 | 7 | Cursor Mode 9 on object |
3 | 0 | Look at character |
3 | 1 | Interact with character |
3 | 2 | Speak to character |
3 | 3 | Use inventory on character |
3 | 5 | Pick up character |
3 | 6 | Cursor Mode 8 on character |
3 | 7 | Cursor Mode 9 on character |
4 | 1 | Look at nothing (i.e. no hotspot) |
4 | 2 | Interact with nothing |
4 | 3 | Use inventory with nothing |
4 | 4 | Talk to nothing |
5 | 0 | Look at inventory |
5 | 1 | Interact with inventory (currently not possible) |
5 | 2 | Speak to inventory |
5 | 3 | Use an inventory item on another |
5 | 4 | Other click on inventory |
NOTE: the "Character stands on hotspot" event does not trigger this function, nor will it be triggered if there is an "Any click" event handler defined, nor if the player clicks on nothing (hotspot 0)
on_call
(int value) on_call
This callback can only be declared on Room Script.
It's called after the function CallRoomScript(value)
is executed, but not immediately. You can read an arbitrary integer value passed from CallRoomScript
. Additional information is available here.