Image controls are used to display large images stored in the database. Image controls support tokens and pointers
as well as a toggleable grid with variable dimensions.
The control internally supports the "token" and "shortcut" dragdata types, with the former creating new
token instances on the control, and the latter creating shortcut icons.
Definition
<imagecontrol name="..."
>
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<indicators
>
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This section contains names for bitmaps used to indicate image control state |
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<availability
>
...
</availability>
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The name of the icon resource used to notify the host user that all clients have downloaded the image being displayed |
|
<locked
>
...
</locked>
|
The name of the icon resource used to notify that the drawing layer is locked |
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<zoom
>
...
</zoom>
|
The name of the icon resource used to notify that the active zoom level is different from 100% |
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<shortcuts
>
...
</shortcuts>
|
The name of the icon resource used to notify the host user that the shortcuts are being displayed and can be manipulated |
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<loading
>
...
</loading>
|
The name of the icon resource used for client users to draw a notification in the middle of the control when the image is being downloaded |
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</indicators>
|
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<shortcut
>
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Information about the image used to represent shortcuts |
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<icon
>
...
</icon>
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The name of the icon resource used to draw the shortcut |
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<hotspot
>
...
</hotspot>
|
The offset on the bitmap representing the location to pinpoint shortcut, as two comma separated numbers |
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</shortcut>
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<drawing
>
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<defaultsize
>
...
</defaultsize>
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The size used for the initial image control contents if the image contains no bitmap image, i.e. is a pure drawing |
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</drawing>
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</imagecontrol>
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Interface
addToken
function addToken(
prototypename, x, y
)
This function creates a new token instance in the control. The name of the prototype should be treated as an identifier obtained from another
location (such as a tokencontrol or another imagecontrol) and not be directly edited by the calling script.
Parameters
prototypename (string)
The string identifying the token prototype to use for creating the token instance
x (number)
The X coordinate the token should be created at
y (number)
The Y coordinate the token should be created at
Return values
(tokeninstance)
A reference to a
tokeninstance object representing the newly created token or
nil in case of error.
deleteDrawing
function deleteDrawing(
)
Deletes the entire drawing layer.
enableGridPlacement
function enableGridPlacement(
)
Enables grid placement mode, using the currently set grid placement tool.
getDrawingTool
function getDrawingTool(
)
Gets the currently selected drawing tool. Valid values are "paint" and "erase".
Return values
(string)
The current paint mode, or nil if paint mode is not active
getGridHexElementDimensions
function getGridHexElementDimensions(
)
This utility function helps with the location of points on the hex grid. Hexes are drawn by treating the grid size as the number of pixels between
opposing straight sides (vertical or horizontal depending on the type). The hexagonal shape is then calculated in an integer approximation by calculating
a "half height" value (half of the grid size, rounded down) and a "quarter width" (grid size * tan(30 degrees) / 2, rounded down). The size of the hex
is then considered to be twice the half height from straight side to straight side, and four times the quarter width along the longest axis.
Return values
(number)
The quarter width of the hex
(number)
The half height of the hex
getGridOffset
function getGridOffset(
)
Returns the offset of the first grid square in the top left corner of the image. The offsets will be different from zero
as a result of the grid not being perfectly aligned with the top left corner of the image itself. The values will vary from
zero to -((grid size) - 1).
Return values
(number)
The horizontal offset of the grid
(number)
The vertical offset of the grid
getGridSize
function getGridSize(
)
Get the size of the grid squares in pixels. The grid is rectangular, i.e. the height and width of the squares is the same.
Return values
(number)
The size of the grid squares in pixels. If the grid is disabled, returns 0.
getGridType
function getGridType(
)
Returns the type of grid currently active. Valid types are "square", "hexcolumn" (hexes stacked vertically) and "hexrow" (hexes stacked horizontally).
Return values
(string)
The type of grid or nil if the grid is disabled
getImageSize
function getImageSize(
)
Returns the size of the bitmap displayed in the image control.
Return values
(number)
The width on the image.
(number)
The height on the image.
getMaskTool
function getMaskTool(
)
Get the currently active mask manipulation tool. Valid values are "maskselection" and "unmaskselection".
Return values
(string)
The current masking tool, or nil if mask draw mode is not active
getTokens
function getTokens(
)
Retrieve a list of all tokens in the control.
Return values
(table)
A table with integer index values containing references to
tokeninstance objects contained in the control
getViewpoint
function getViewpoint(
)
Returns data on the current viewpoint of the user. The viewpoint is determined by the center point of the portion of image
being viewed in the control as well as the used zoom level.
Return values
(number)
The X coordinate on the image acting as the center point of the viewpoint
(number)
The Y coordinate on the image acting as the center point of the viewpoint
(number)
The zoom level being used (a value of 1.0 represents 100% zoom)
hasDrawing
function hasDrawing(
)
Checks if the control has a drawing layer. (i.e. there is at least one line drawn)
Return values
(boolean)
Returns true if the layer is enabled, or false if it is disabled
hasGrid
function hasGrid(
)
Checks if the control has the image grid enabled.
Return values
(boolean)
Returns true if the grid is on, or false if it is off
hasMask
function hasMask(
)
Checks if the control has a mask layer.
Return values
(boolean)
Returns true if the layer is enabled, or false if it is disabled
onDrawStateChanged
event
function onDrawStateChanged(
tool
)
If present, this function is called when the draw tool is changed.
Parameters
tool (string)
The selected draw tool, or nil if drawing mode was exited.
onDrawingSizeChanged
event
function onDrawingSizeChanged(
)
If present, this function is called when the drawing surface size is changed for drawing only imagecontrols.
onGridStateChanged
event
function onGridStateChanged(
type
)
If present, this function is called whenever the attributes of the grid on an image changes. (i.e. grid type, grid size, grid offset, grin on/off)
Parameters
type (string)
One of the strings "square", "hexcolumn" or "hexrow", depending on the current grid type, or nil if the grid is disabled
onMaskingStateChanged
event
function onMaskingStateChanged(
tool
)
If present, this function is called when the mask manipulation tool is changed.
Parameters
tool (string)
The selected mask manipulation tool, or nil if mask draw mode was exited.
onMeasurePointer
event
function onMeasurePointer(
pixellength, pointertype, startx, starty, endx, endy
)
If present, this function is called to calculate a length label for a pointer in the control. This function allows for the use of customized
length values that are based on a map scale or a grid value setup.
To turn off the label, return the empty string.
Warning
This calculation is performed as part of the screen rendering process. Very complicated calculations may adversely affect the performance
of the application.
Parameters
pixellength (number)
The length of the pointer in pixels
pointertype (string)
The type of the pointer: "arrow", "circle", "cone", "rectangle"
startx (number)
The x coordinate of pointer origination point
starty (number)
The y coordinate of pointer origination point
endx (number)
The x coordinate of pointer termination point
endy (number)
The y coordinate of pointer termination point
Return values
(string)
The label applied to the pointer
onMeasureVector
event
function onMeasureVector(
token, vector
)
If present, this function is called to calculate a length label for a movement vector at a locked token. This function allows for the use of
customized length values that are based on a map scale or a grid value setup.
To turn off the label, return the empty string.
Warning
This calculation is performed as part of the screen rendering process. Very complicated calculations may adversely affect the performance
of the application.
Parameters
token (tokeninstance)
A reference to a
tokeninstance object representing the token the vector is drawn from. This reference can be used
to retrieve information about the token.
(table)
A table with integer indices ranging from 1 to the number of path segments in the vector, representing the lengths of the segments.
Each index contains a subtable with the indices "x" and "y" that contain the corresponding segment length components. For example,
vector[1].x contains the length of the first path segment in the horizontal direction, and #vector
indicates the number of path segments.
Return values
(string)
The label applied to the vector
onPointerSnap
event
function onPointerSnap(
startx, starty, endx, endy, type
)
If present, this function is executed whenever pointers placed on this control are moved. The new coordinates of the pointer are given
as parameters, and the returned values are used as replacements.
When snap is disabled, the function should return the original values. See hasGrid, getGridSize and
getGridOffset for snapping based on the image grid.
Parameters
startx (number)
The X coordinate for the starting point of the pointer. For circles and rectangles, the center point.
starty (number)
The Y coordinate for the starting point of the pointer. For circles and rectangles, the center point.
endx (number)
The X coordinate of the ending point of the pointer. For circles and rectangles, this is the point on the shape closest
to the mouse cursor when adjusting the pointer.
endy (number)
The Y coordinate of the ending point of the pointer. For circles and rectangles, this is the point on the shape closest
to the mouse cursor when adjusting the pointer.
type (string)
The type of the pointer being adjusted. This string has one of the following values: "arrow", "circle", "cone" or "rectangle".
Return values
(number)
The desired snapped X coordinate of the pointer starting point.
(number)
The desired snapped Y coordinate of the pointer starting point.
(number)
The desired snapped X coordinate of the pointer end point.
(number)
The desired snapped Y coordinate of the pointer end point.
onTokenAdded
event
function onTokenAdded(
token
)
This function is executed when a new token instance is created in the control. As of v2.8, this function will be called when the imagecontrol is initialized for each existing token.
Parameters
token (tokeninstance)
onTokenSnap
event
function onTokenSnap(
token, x, y
)
If present, this function is executed whenever tokens placed on this control are moved. The new coordinates of the token are given
as parameters, and the returned values are used as replacements.
When snap is disabled, the function should return the original values. See hasGrid, getGridSize and
getGridOffset for snapping based on the image grid.
Parameters
token (tokeninstance)
x (number)
The X coordinate of the token instance
y (number)
The Y coordinate of the token instance
Return values
(number)
The snapped X coordinate for the token instance
(number)
The snapped Y coordinate for the token instance
preload
function preload(
)
Sends the image to all connected clients without sharing the image, making the image instantly available when later shared.
setDrawingSize
function setDrawingSize(
width, height, offsetx, offsety
)
Sets the available canvas for drawing on non-bitmap image spaces.
Warning
This function can only be called from the host. Also, this function will only work if the image control does not contain a bitmap image (i.e. a pure drawing).
Parameters
width (number)
The desired canvas width
height (number)
The desired canvas height
offsetx (number)
The horizontal offset of the current canvas space within the new canvas dimensions
offsety (number)
The vertical offset of the current canvas space within the new canvas dimensions
setDrawingTool
function setDrawingTool(
type
)
Sets the drawing tool, enabling or disabling painting mode accordingly. Valid values are "paint" and "erase", other values will cause
drawing mode to be exited.
Parameters
type (string)
The desired draw mode
setGridOffset
function setGridOffset(
offsetx, offsety
)
Sets the offset of the first grid square in the top left corner of the image. The valid values for the offsets range from
zero to -((grid size) - 1), any values not in this range will be converted to fit the interval.
Parameters
offsetx (number)
The horizontal grid offset
offsety (number)
The vertical grid offset
setGridSize
function setGridSize(
size
)
Set the size of the image grid. Setting this value to 0 will disable the grid.
Parameters
size (number)
The size of the grid in pixels
setGridToolType
function setGridToolType(
type
)
Sets the type of the grid placement tool used. The possible values are "square" and "hex". The hex tool places a hex grid whose type is determined
by the direction of mouse movement while placing the grid.
Parameters
type (string)
The desired tool type
setGridType
function setGridType(
type
)
Sets the type of grid currently active. Valid types are "square", "hexcolumn" (hexes stacked vertically) and "hexrow" (hexes stacked horizontally).
Parameters
type (string)
The desired type for the grid
setMaskEnabled
function setMaskEnabled(
state
)
Enables or disables the image mask.
Parameters
state (boolean)
The desired mask state
setMaskTool
function setMaskTool(
type
)
Sets the mask manipulation tool, enabling or disabling mask drawing mode accordingly. Valid values are "maskselection" and "unmaskelection", other values will cause
mask draw mode to be exited. If there is no active mask on the image, will have no effect.
Parameters
type (string)
The desired mask draw mode
setTokenOrientationCount
function setTokenOrientationCount(
count
)
Sets the number of different token orientations available in this image, evenly spread out along a full revolution.
Only scripts running on the session host can set this property.
Parameters
count (number)
The desired number of orientations
setViewpoint
function setViewpoint(
viewx, viewy, zoom
)
Sets the active viewpoint of the user. The image viewpoint is repositioned so that the given coordinates on the image are centered in
the control with the specified zoom level active.
Parameters
viewx (number)
The desired horizontal view point center coordinate
viewy (number)
The desired vertical view point center coordinate
zoom (number)
The zoom level as a decimal number, with 1.0 being 100% zoom
