6 Standard dialog boxes

QTk offers the following standard dialog boxes:

• Save file selection

• Load file selection

• Color selection

• Canvas print parameters

If the application runs on a Windows platform, the first 3 dialog boxes are the standard one from Windows.

6.1 Save and load dialog boxes

The save and load dialog boxes are spawned by:

{QTk.dialogbox save(defaultextension:DE
                    filetypes:FT
                    initialdir:ID
                    initialfile:IF
                    title:Title
                    1:R)}

and

{QTk.dialogbox load(defaultextension:DE
                    filetypes:FT
                    initialdir:ID
                    initialfile:IF
                    title:Title
                    1:R)}

Example:

Result={QTk.dialogbox load(defaultextension:"qdw" 
                           initialdir:"." 
                           title:"Load QTkDrawing..." 
                           initialfile:"" 
                           filetypes:q(q("QTkDraw files" q(".qdw"))
                                       q("All files" q("*"))) $)}

The parameters are:

• defaultextension: a virtual string specifying the default extension for the file if the user doesn't type one. If not specified, an empty string is assumed.

• filetypes: a record of the form q(R1 .. Rx) where Ri are records of the form q(TextDesc q(Extension1 .. Extensiony) with TextDesc and Extensioni virtual strings. This parameter specifies different filters for displaying files. Each Ri specifies one filter, TextDesc being the textual description shown to the user. Each Extensioni specifies an extension valid for this filter. If not specified, q("All files" q("*")) is assumed.

• initialdir: a virtual string specifying the initial directory. If not specified, "." is assumed.

• initialfile: a virtual string specifying a default file name. If not specified, an empty string is assumed.

• title: a virtual string specifying the title of the dialog box. If not specified, "Open" or "Save" are assumed.

• 1: a free variable that is bound to the filename selected by the user or to nil if he cancelled.

6.2 Color dialog box

The color dialog box is spawned by:

{QTk.dialogbox color(initialcolor:IC
                     title:Title
                     1:R)}

Example:

Result={QTk.dialogbox color(initialcolor:c(255 0 0)
                            title:"Select a color..." $)}

The parameters are:

• initialcolor: the initial color (see Section 8.2). If not specified, a random color is picked by default.

• title: a virtual string specifying the title of the dialog box. If not specified, "Color" is assumed.

• 1: a free variable that is bound to the filename selected by the user or to nil if he cancelled.

6.3 Print Canvas dialog box

Canvases can be printed by their postscript method. The print canvas dialog box can be used to let the user interactively specify all the parameters of this method. To help the user correctly choose the area to print, a rough copy of the canvas is done inside the dialog box.

The print canvas dialog box is spawned by:

{QTk.dialogbox printcanvas(canvas:C
                           title:Title
                           region:R
                           zoom:Z
                           rotate:R
                           fit:F
                           pagewidth:PW
                           pageheight:PH
                           pagex:PX
                           pagey:PY
                           width:W
                           height:H
                           colormode:CM
                           x:X
                           y:Y
                           1:R)}

Example:

C
{{QTk.build td(canvas(glue:nswe handle:C))} show}
{C create(rectangle 10 10 100 100)}
Result={QTk.dialogbox printcanvas(canvas:C $)}
{C postscript(colormode:Result.colormode
              pagewidth:Result.pagewidth
              pagex:0.0
              pagey:0.0
              pageanchor:sw
              rotate:Result.rotate
              width:Result.tkwidth
              height:Result.tkheight
              x:Result.tkx
              y:Result.tky
              file:"out.ps")

The parameters are:

• canvas: the handle of the canvas to print.

• title: a virtual string specifying the title of the dialog box. If not specified, "Postscript Generation Options" is assumed.

• region: a list of 4 integers [X Y Width Height] specifying the region of the canvas that is printable. X and Y is the coordinate of the top-left corner, and Width and Height the width and height of this area. If not specified, [0 0 200 200] is assumed.

• zoom: a real specifying a zoom factor to apply to the area to print. If not specified, 1.0 is assumed.

• rotate: a boolean specifying the canvas must be rotated 90 degrees when printed or not. If not specified, false is assumed.

• fit: a boolean specifying if the area to print must be stretched to fit the whole page or not. If not specified, false is assumed.

• pagewidth: a virtual string representing the page width. Valid strings are composed of an integer value followed by one of these letters: c, m, i, p. c stands for centimers, m for millimeters, i for inches and p for picas. If not specified, the string "210m" is assumed.

• pageheight: a virtual string representing the page height. Valid strings are valid strings for the pagewidth parameter. If not specified, the string "297m" is assumed.

• pagex: a virtual string representing the left margin of the page. Valid strings are valid strings for the pagewidth parameter. If not specified, the string "10m" is assumed.

• pagey: a virtual string representing the top margin of the page. Valid strings are valid strings for the pagewidth parameter. If not specified, the string "10m" is assumed.

• width: an integer specifying the width of the area of the canvas to print. If not specified, the horizontal space available from the print region of the canvas is assumed.

• height: an integer specifying the height of the area of the canvas to print. If not specified, the vertical space available from the print region of the canvas is assumed.

• colormode: an atom specifying if the page must be printed in color, shades of gray or pure black and white. Valid values are color, gray and mono. If not specified, mono is assumed.

• x: an integer specifying the horizontal origin of the area of the canvas to print. If not specified, 0 is assumed.

• y: an integer specifying the horizontal origin of the area of the canvas to print. If not specified, 0 is assumed.

• 1: a free variable that is bound to nil if the user cancelled, or that is bound to a record containing a feature for each parameter described here. Note that the semantics of the parameters width, height, x and y are slightly different from those of the postscript method of canvases. Consequently, the returned record of printcanvas also has the features tkwidth, tkheight, tkx and tky that contain the values that should be given to the width, height, x and y parameters of the postscript method of canvases (see example).