Difference between revisions of "Manual/Plugins/Scripting"

Latest revision as of 10:55, 11 November 2013

Scripts are in QtScript aka ECMAScript aka JavaScript.

The details of the language are specified in the Qt ECMAScript reference. This page focuses on functions and objects specific to Knotter.

Geometry

Point

A wrapper to QPointF.

Constructors
Name	Type	Description
`new Point()`	`Point`	`new Point(0,0)`
`new Point( Point other )`	`Point`	Copy point `other`
`new Point( Number x, Number y )`	`Point`	Create point with given coordinates
External functions
Name	Type	Description
`opposite( Point p )`	`Point`	`new Point(-p.x,-p.y)`
`distance(Point a, Point b)`	`Number`	Distance from a and b

Line

A wrapper to QLineF most of the functionality of QLineF is also present in line.

Constructors
Name	Type	Description
`new Line()`	`Line`	Empty line
`new Line( Line other )`	`Line`	Copy line `other_line`
`new Line( point1, point2 )`	`Line`	Line from point `point1` to `point2`
Properties
Name	Type	Description
`p1`	`Point`	Starting point of the line
`p2`	`Point`	End point of the line
`x1`	`Number`	`p1.x`
`x2`	`Number`	`p2.x`
`y1`	`Number`	`p1.y`
`y2`	`Number`	`p2.y`
`angle`	`Number`	Angle of the line in degrees. An angle of 0° is a horizontal line pointing to the right.
`length`	`Number`	Length of the line (distance between `p1` and `p2`
`dx`	`Number`	`p1.x-p2.x`
`dy`	`Number`	`p1.y-p2.y`
Methods
Name	Type	Description
`intersect ( Line other )`	`Point`	Return the intersection point between the current line and other
`normalVector()`	`Line`	Returns a line that is perpendicular to this line with the same starting point and length.
`unitVector()`	`Line`	Returns the unit vector for this line, i.e a line starting at the same point as this line with a length of 1.0.
`pointAt(Number t)`	`Point`	Returns the point at the parameterized position specified by t. The function returns the line's start point if t = 0, and its end point if t = 1.
`translate(Point offset)`	`void`	Translate the line by `offset`
`translate(Number x,Number y)`	`void`	`translate(point(x,y))`

Polygon

Name	Type	Description
`new Polygon()`	`Polygon`	Create an empty polygon.
`new Polygon(vertices)`	`Polygon`	Create a polygon with given vertices.
`vertices`	`Array[Point]`	Vertices of the polygon.
`contains(point)`	`Boolean`	Whether the point is inside the polygon.
`contains(x,y)`	`Boolean`	`contains(new Point(x,y))`.
`add_vertex(point)`	`void`	Appends a vertex to `vertices`.

Misc

global functions

Name	Type	Description
`print(...)`	`void`	Writes all arguments to standard output and the Script_Console.
`run_script(filename)`	`void`	executes the given script file in the current context.

Color

Constructors
Name	Type	Description
`new Color()`	`Color`	Creates a transparent black color
`new Color(string)`	`Color`	Create a color from a color name eg: #ff00ff, red
`new Color(r,g,b,a=255)`	`Color`	Create a color from rgb components [0-255]
`new Color(color)`	`Color`	Copy color
Properties
Name	Type	Description
`alpha`	`Number`	Transparency [0-255]
`red`	`Number`	RGB red channel [0-255]
`green`	`Number`	RGB green channel [0-255]
`blue`	`Number`	RGB blue channel [0-255]
`hue`	`Number`	HSV hue channel [0-360]
`saturation`	`Number`	HSV saturation channel [0-255]
`value`	`Number`	HSV value channel [0-255]
`cyan`	`Number`	CMYK cyan channel [0-255]
`magenta`	`Number`	CMYK magenta channel [0-255]
`yellow`	`Number`	CMYK yellow channel [0-255]
`black`	`Number`	CMYK black channel [0-255]
Number
Name	Type	Description
`rgb(r,g,b,a=255)`	`Color`	Same as `new Color(r,g,b,a)`
`hsv(h,s,v,a=255)`	`Color`	Creates a color from its HSV components
`hsl(h,s,l,a=255)`	`Color`	Creates a color from its HSL components
`cmyk(c,m,y,k,a=255)`	`Color`	Creates a color from its CMYK components

Path

Object used in cusp plugins to draw the knot line, wrapper to the Knotter internal Path_Builder class. Cannot be constructed by the user.

Methods
Name	Type	Description
`add_line( Point p1, Point p2 )`	`void`	Draw a straight line from `p1` to `p2`
`add_quad( Point p1, Point control, Point p2`	`void`	Draw a quadratic curve from `p1` to `p2` with control point `control`
`add_cubic( Point p1, Point control1, Point control2, Point p2 )`	`void`	Draw a cubic curve from `p1` to `p2` with control points `control1` and `control2`

Graph

The graph for a given knot.

Name	Type	Description
`new graph()`	`Graph`	Creates an empty graph
`nodes`	`Array[Node]`	Nodes in the graph
`edges`	`Array[Edge]`	Edges in the graph
`style`	`Graph.Style`	Graph Style
`selected_nodes`	`Array[node]`	List of the selected nodes
`add_node(point)`	`Node`	Creates a new node
`add_node(x,y)`	`Node`	Creates a new node
`remove_node(node)`	`void`	Remove node from the graph
`remove_edge(edge)`	`void`	Remove edge from the graph
`connect(node1,node2)`	`Edge`	Creates a new edge
`node_at(point)`	`Node`	Get the node at the given location
`node_at(x,y)`	`Node`	Get the node at the given location
`node_at(point,radius)`	`Array[Node]`	Get the nodes within given distance from location
`node_at(x,y,radius)`	`Array[Node]`	Get the nodes within given distance from location
`append( file_name, keep_style=false, offset=Point() )`	`Boolean`	Add nodes and edges from a file. keep_style controls whether the nodes should have their custom style set to override the graph style in order to follow the style from the file.
`append(Graph other)`	`void`	The contents of the other graph are copied to this graph.
`clear()`	`void`	Remove all edges and nodes

Node

Name	Type	Description
`pos`	`Point`	Position of the node.
`x`	`Number`	`pos.x`.
`y`	`Number`	`pos.y`.
`selected`	`Boolean`	Whether the node is selected.
`edges`	`Array[Edge]`	(Read-Only) Edges with this node as vertex.
`style`	`Node.Style`	Contains the style features that this node overrides from the graph
`has_edge_too(Node other)`	`Boolean`	Whether there is an edge from `this` to `other`.
`edge_to(Node other)`	`Edge`	Edge connecting `this` and `other`.

Edge

Name	Type	Description
`vertex1`	`Node`	One of the vertices of the edge
`vertex2`	`Node`	One of the vertices of the edge
`line`	`Line`	Line from `vertex1.pos` to `vertex2.pos`
`midpoint`	`Point`	Point at the middle of the edge
`style`	`Edge.Style`	Contains the style features that this edge overrides from the graph
`is_vertex(node)`	`Boolean`	Whether the node is a vertex of the edge
`other(node)`	`Node`	If the given node is one of its vertices, return the other vertex

Graph.Style

Default style for nodes and edges and graph appearance

Name	Type	Description
`crossing`	`Edge.Style`	Default edge style
`cusp`	`Node.Style`	Default node style
`colors`	`Array[Color]`	(Read-Only) Colors

Node.Style

For nodes, a single style feature can be removed by setting it to undefined

Name	Type	Description
`angle`	`Number`	Minimum angle required to trigger a cusp
`curve`	`Number`	Size of the curve control handles
`distance`	`Number`	Distance of the tip of the cusp from the node
`shape`	`String`	Name of the cusp shape. Possible values are the elements of `knotter.cusp_shapes`
`clear()`	`void`	Reset all features

Edge.Style

For nodes, a single style feature can be removed by setting it to undefined

Name	Type	Description
`curve`	`Number`	Size of the curve control handles
`gap`	`Number`	Size of the gap for a rope passing under a crossing
`slide`	`Number`	Slide the crossing position [0-1]
`type`	`String`	The name of the edge type. Possible values are the elements of `knotter.edge_types`
`clear()`	`void`	Reset all features

Interaction with Knotter

system

Object that allows interactions with the system.

Name	Type	Description
`read_file(file_name)`	`ByteArray`	Read file contents
`write_file(file_name,data)`	`Boolean`	Write data to file.`data` can be either a string or a ByteArray. Returns true if the output was successful.
`temp_path()`	`String`	Returns the system temporary directory path.
`unique_temp_file(base_name,extension)`	`String`	Returns a safe absolute file name to create a unique temporary file with the given extension.
`file_exists(file_name,readable=false,writable=false)`	`Boolean`	Check if a file with the given permissions exists in the file system.

knotter

Object with information on Knotter.

Name	Type	Description
`version`	`String`	Knotter version
`has_version(Number major,Number minor)`	`Boolean`	Whether the current version is greater than major.minor.0
`cusp_shapes`	`Array[String]`	Array of names of the available cusp shapes
`edge_types`	`Array[String]`	Array of names of the available edge types

window

Perform some basic operations to Knotter main window.

Name	Type	Description
`current_file`	`String`	(Read only) File name of the knot in the active tab
`current_tab`	`Number`	Index of the active tab
`open_tabs`	`Number`	Number of open tabs
`document`	`Document`	Document corresponding to the current tab.
`open( String file )`	`Boolean`	Open file, returns true if successful
`open()`	`Boolean`	Create an new tab
`screenshot(String file, String widget_name="")`	`void`	Take a screenshot of the given widget (or the main window if widget_name is empty).

window.dialog

An object that contains several functions to display simple dialogs to the user.

Name	Type	Description
`information(message,title="")`	`void`	Display an information dialog
`warning(message,title="")`	`void`	Display a warning dialog
`critical(message,title="")`	`void`	Display an error dialog
`question(message, title="", button_0="OK", button_1="", button_2="")`	`Number`	Display a dialog asking a question. For every non-empty button text a button is shown. Returns the index of the button that the user pressed.
`get_open_file(title="",filters="")`	`String`	Show a dialog to open a file. Filters is in the form "Text (.txt);;Image (.svg .png)", Returns the selected file name or an empty string if the user canceled the dialog.
`get_number(message, title="", default_value=0, min=MIN, max=MAX)`	`Number`	Asks a dialog for a number. Returns NaN if the user canceled.
`get_integer(message, title="", default_value=0, min=MIN, max=MAX)`	`Number`	Just like get_number but only integers values are allowed
`get_text(message,title="",default_value=)`	`String`	Ask the user for a line of text.
`information(get_item,title="",items=[])`	`String`	Ask the user to select an item from the list. Returns the string representing the value or an empty string if the user canceled the dialog.
`load_widget(file_name)`	`QWidget`	Load a widget from a Ui file
`progress_dialog(message, maximum=0, cancel_button="Cancel" )`	`QProgressDialog`	Creates a progress dialog.

gui

Utility object that creates wrappers to Qt widgets in order to access some of their functionality that is not usually available to scripts.

Name	Type	Description
`table_widget(QTableWidget)`	`gui.table_widget`	Creates a wrapper to a QTableWidget.

gui.table_widget

Name	Type	Description
`table`	`QObject`	The wrapped QTableWidget.
`set_value(row, column, value)`	`void`	Change the value in the given cell.
`get_value (row,column)`	`String`	Get the value in the given cell.
`append_row([values])`	`void`	Append a row with the given values.
`current_row()`	`Number`	The currently selected row or -1.
`current_column()`	`Number`	The currently selected column or -1.
`value_changed(row,column,value)`	`(Signal)`	Emitted when the user changes the content of a cell.

Document

The document from which the script was called. While window.document may change, the global document object will be the same during the entire script.

Name	Type	Description
`filename`	`String`	The name of the file for this document.
`graph`	`Graph`	The graph contained by the document.
`grid`	`Grid`	The grid used by the document.
`insert(graph,message="ScriptInsert")`	`Boolean`	Insert graph in the document. The inserted graph will have to be placed by the user in the desired location. Returns whether insertion has been successful.
`render`	`Document.render`	Document renderer
`begin_macro(message)`	`void`	Wrap following edits to the document in a macro, the message will be the text displayed in the action history. Macros can be nested.
`end_macro()`	`void`	End current macro. For each call to `begin_macro` there should be a call to `end_macro`.

Document.render

Renders the document in several formats.

Name	Type	Description
`draw_graph = false`	`Boolean`	Whether the graph should be rendered as well.
`knot()`	`String`	Knot file XML.
`svg()`	`String`	SVG XML.
`raster( width=0, height=0, format="PNG", quality=0, background=new Color() )`	`ByteArray`	Raster. If `width` or `height` aren't positive, their value is deduced by the graph size. `format` is a string identifying the image format. `quality` in [0,100] is the opposite of the compression. For JPEG it may be a good idea to set to a high value for other formats low values mean more compression. `background` Background color, transparent will look black in formats that don't have an aplpha channel.

Grid

The grid displayed by a document object.

Name	Type	Description
`size`	`Number`	Size of a grid cell.
`origin`	`Point`	Position of the grid origin
`enabled`	`Boolean`	Whether the grid is displayed or not.
`shape`	`String`	One of SQUARE, TRIANGLE1 or TRIANGLE2.
`enable()`	`void`	Shorthand for `grid.enabled = true;`.
`disable()`	`void`	Shorthand for `grid.enabled = false;`.

Plugin-specific objects

All Plugins

All plugins can access the object plugin that contains the information from the plugin data.

Cusp Plugins

Name	Type	Description
`angle`	`Number`	The angle between input and output edge
`cusp_angle`	`Number`	Style setting, if `angle > cusp_angle` , draw a cusp
`handle_length`	`Number`	Style setting, "curve" style parameter in the UI
`start_handle`	`Line`	Starting point for lines, start_handle.p1 will be connected to the path forming the crossing
`finish_handle`	`Line`	Ending point for lines, finish_handle.p1 will be connected to the path forming the crossing
`cusp_point`	`Point`	Pre-computed cusp point location
`node_point`	`Point`	Position of the node between the two edges
`input_edge`	`Line`	Line corresponding to the input edge
`output_edge`	`Line`	Line corresponding to the output edge
`path`	`Path`	Object used to build the path
`direction`	`Number`	-1 or +1 depending on the direction of the angle (clockwise or counter)

Guidelines

A cusp is expected to render a path from start_handle.p1 to finish_handle.p1.

start_handle.p2 and finish_handle.p2 may be used as control points.

If angle > cusp_angle the line should pass through cusp_point

Example

Follows the code to replicate the built-in rounded cusp.

// When angle is large enough, draw the cusp
if ( angle > cusp_angle ) 
{
    // Create a "handle" that on cusp_point with size handle_length to determine the control points
    var handle = new Line(start_handle.p1,finish_handle.p1);
    handle.translate(cusp_point);
    handle.translate(opposite(start_handle.p1));
    handle.length = handle_length;
    var h2 = handle.p2;
    handle.length = -handle_length;
    var h1 = handle.p2;
    // Use the control points to render the cusp
    path.add_cubic ( start_handle.p1, start_handle.p2, h1, cusp_point );
    path.add_cubic ( finish_handle.p1, finish_handle.p2, h2, cusp_point );
}
else
{
    // Don't draw a cusp, just a curve from start_handle to finish_handle
    
    if ( distance(start_handle.p1,finish_handle.p1) < start_handle.length + finish_handle.length )
    {
        // The two edges are very close together, avoid artifacts with a simpler curve
        var midpoint = Point( (start_handle.p2.x+finish_handle.p2.x)/2,
                              (start_handle.p2.y+finish_handle.p2.y)/2 );
        path.add_quad(start_handle.p1,midpoint,finish_handle.p1);
    }
    else
    {
        // There's enough room to draw a cubic curve
        path.add_cubic(start_handle.p1,start_handle.p2,finish_handle.p2,finish_handle.p1);
    }
}

Edge Plugins

Name	Type	Description
`TOP_RIGHT, BOTTOM_LEFT, BOTTOM_RIGHT, TOP_LEFT`	`Number`	Constant values to identify the input/output handle.
`edge`	`Edge`	The edge that is requesting the script.
`style`	`Edge.Style`	The edge style containing default values from the graph.
`handle`	`Number`	The input handle (See above for values that may identify it).
`path`	`Path`	Object used to build the path. (Only available to the `traverse` script)
`result`	`Number`	The output handle id. The script must write a value to this variable. (Only available to the `traverse` script)
`result`	`Line`	The output handle. The script must write a value to this variable. (Only available to the `handle` script)

Guidelines

A custom crossing requires two scripts:

traverse: that will draw to the path (if needed) and return the direction the thread should move once passed the current edge
handle: that will return a line corresponding to the given handle id.

These snippets will be executed after the execution of the main script file. It's recommended that the scrip file provides useful functions that will be called by these snippets.

Example

The following example replicates the default crossing:

{
    "author" : "Mattia Basaglia",
    "description" : "An implementation of the built-in normal edge type as a plugin, disabled by default.\n\nThis plugin serves as an example on how to create crossing plugins.",
    "license" : "GPLv3+",
    "name" : "Example Edge",
    "requires" : "0.9.6",
    "script" : "example_edge.js",
    "type" : "crossing",
    "version" : "1",
    "traverse" : "var result = traverse(edge,handle,style);",
    "handle" : "var result = handle_line(edge,handle,style);",
    "auto_enable"   : false,
    "category" : "Example"
}

function traverse(edge,handle,style)
{
    var next = 0;
    if ( handle == TOP_RIGHT )
        next = BOTTOM_LEFT;
    else if ( handle == BOTTOM_RIGHT )
        next = TOP_LEFT;
    else if ( handle == BOTTOM_LEFT )
        next = TOP_RIGHT;
    else if ( handle == TOP_LEFT )
        next = BOTTOM_RIGHT;

   if ( handle == TOP_LEFT || next == TOP_LEFT )
       path.add_line(handle_line(edge,handle,style).p1,
                     handle_line(edge,next,style).p1
                     );
    return next;
}

function deg2rad(deg)
{
    return deg / 180 * Math.PI;
}

function handle_line(edge,handle,style)
{

    var handle_angle = 0;
    if ( handle == TOP_RIGHT )
        handle_angle = Math.PI/4.0;
    else if ( handle == TOP_LEFT )
        handle_angle = Math.PI*3.0/4.0;
    else if ( handle == BOTTOM_LEFT )
        handle_angle = Math.PI*5.0/4.0;
    else if ( handle == BOTTOM_RIGHT )
        handle_angle = Math.PI*7.0/4.0;

    handle_angle += deg2rad(edge.line.angle);
    var p1 = edge.line.pointAt(style.slide);
    p1.x = p1.x+style.gap/2*Math.cos(handle_angle);
    p1.y = p1.y-style.gap/2*Math.sin(handle_angle);

    var p2 = new Point(
            p1.x+style.curve*Math.cos(handle_angle),
            p1.y-style.curve*Math.sin(handle_angle)
    );

    return new Line(p1,p2);
}

@@ Line 217: / Line 217: @@
 {{object list item|write_file(file_name,data)|Boolean|Write data to file.{{js|data}} can be either a string or a ByteArray. Returns true if the output was successful.}}
 {{object list item|temp_path()|String|Returns the system temporary directory path.}}
+{{object list item|unique_temp_file(base_name,extension)|String|Returns a safe absolute file name to create a unique temporary file with the given extension.}}
+{{object list item|file_exists(file_name,readable{{=}}false,writable{{=}}false)|Boolean|Check if a file with the given permissions exists in the file system.}}
 {{object list end}}
@@ Line 285: / Line 288: @@
 {{object list item|grid|Grid|The grid used by the document.}}
 {{object list item|insert(graph,message{{=}}"ScriptInsert")|Boolean|Insert graph in the document. The inserted graph will have to be placed by the user in the desired location. Returns whether insertion has been successful.}}
-{{object list item|render|Document.Render|Document renderer}}
+{{object list item|render|Document.render|Document renderer}}
 {{object list item|begin_macro(message)|void|Wrap following edits to the document in a macro, the message will be the text displayed in the action history. Macros can be nested.}}
 {{object list item|end_macro()|void|End current macro. For each call to {{js|begin_macro}} there should be a call to {{js|end_macro}}.}}
+{{object list end}}
+===Document.render===
+Renders the document in several formats.
+{{object list begin}}
+{{object list header}}
+{{object list item|draw_graph {{=}} false|Boolean|Whether the graph should be rendered as well.}}
+{{object list item|knot()|String|Knot file XML.}}
+{{object list item|svg()|String|SVG XML.}}
+{{object list item|raster( width{{=}}0, height{{=}}0, format{{=}}"PNG", quality{{=}}0, background{{=}}new Color() )|ByteArray|Raster.<br/>
+If {{js|width}} or {{js|height}} aren't positive, their value is deduced by the graph size.<br/>
+{{js|format}} is a string identifying the image format.<br/>
+{{js|quality}} in [0,100] is the opposite of the compression. For JPEG it may be a good idea to set to a high value for other formats low values mean more compression.<br/>
+{{js|background}} Background color, transparent will look black in formats that don't have an aplpha channel.}}
 {{object list end}}

Difference between revisions of "Manual/Plugins/Scripting"

Latest revision as of 10:55, 11 November 2013

Contents

Geometry

Point

Line

Polygon

Misc

global functions

Color

Path

Graph

Graph

Node

Edge

Graph.Style

Node.Style

Edge.Style

Interaction with Knotter

system

knotter

window

window.dialog

gui

gui.table_widget

Document

Document.render

Grid

Plugin-specific objects

All Plugins

Cusp Plugins

Guidelines

Example

Edge Plugins

Guidelines

Example

Navigation menu

Search