Dialog Widget Application Header file <X11/Xaw/Dialog.h> Class Header file <X11/Xaw/DialogP.h> Class dialogWidgetClass Class Name Dialog Superclass Form The Dialog widget implements a commonly used interaction semantic to prompt for auxiliary input from a user. For example, you can use a Dialog widget when an application requires a small piece of information, such as a filename, from the user. A Dialog widget, which is simply a special case of the Form widget, provides a convenient way to create a preconfigured form. The typical Dialog widget contains three areas. The first line contains a description of the function of the Dialog widget, for example, the string Filename:. The second line contains an area into which the user types input. The third line can contain buttons that let the user confirm or cancel the Dialog input. Any of these areas may be omitted by the application. Resources When creating a Dialog widget instance, the following resources are retrieved from the argument list or the resource database: Name Class Type Notes Default Value accelerators Accelerators AcceleratorTable NULL ancestorSensitive AncestorSensitive Boolean D True background Background Pixel XtDefaultBackground backgroundPixmap Pixmap Pixmap XtUnspecifiedPixmap borderColor BorderColor Pixel XtDefaultForeground borderPixmap Pixmap Pixmap XtUnspecifiedPixmap borderWidth BorderWidth Dimension 1 children ReadOnly WidgetList R NULL colormap Colormap Colormap Parent's Colormap defaultDistance Thickness int 4 depth Depth int C Parent's Depth destroyCallback Callback XtCallbackList NULL height Height Dimension A Enough space to contain all children icon Icon Bitmap None label Label String "label" mappedWhenManaged MappedWhenManaged Boolean True numChildren ReadOnly Cardinal R 0 screen Screen Screen R Parent's Screen sensitive Sensitive Boolean True translations Translations TranslationTable NULL value Value String no value widget width Width Dimension A Enough space to contain all children x Position Position 0 y Position Position 0 _ icon A pixmap image to be displayed immediately to the left of the Dialog widget's label. label A string to be displayed at the top of the Dialog widget. value An initial value for the string field that the user will enter text into. By default, no text entry field is available to the user. Specifying an initial value for value activates the text entry field. If string input is desired, but no initial value is to be specified then set this resource to "" (empty string). Constraint Resources Each child of the Dialog widget may request special layout resources be applied to it. These constraint resources allow the Dialog widget's children to specify individual layout requirements. Name Class Type Notes Default Value bottom Edge XawEdgeType XawRubber fromHoriz Widget Widget NULL (left edge of Dialog) fromVert Widget Widget NULL (top edge of Dialog) horizDistance Thickness int defaultDistance resource left Edge XawEdgeType XawRubber resizable Boolean Boolean FALSE right Edge XawEdgeType XawRubber top Edge XawEdgeType XawRubber vertDistance Thickness int defaultDistance resource bottom left right top What to do with this edge of the child when the parent is resized. This resource may be any edgeType. See Layout Semantics for details. fromHoriz fromVert Which widget this child should be placed underneath (or to the right of). If a value of NULL is specified then this widget will be positioned relative to the edge of the par- ent. horizDistance vertDistance The amount of space, in pixels, between this child and its left or upper neighbor. resizable If this resource is False then the parent widget will ignore all geometry request made by this child. The parent may still resize this child itself, however. Layout Semantics The Dialog widget uses two different sets of layout seman- tics. One is used when initially laying out the children. The other is used when the Dialog is resized. The first layout method uses the fromVert mand fromHoriz resources to place the children of the Dialog. A single pass is made through the Dialog widget's children in the order that they were created. Each child is then placed in the Dialog widget below or to the right of the widget speci- fied by the fromVert mand fromHoriz mresources. The distance the new child is placed from its left or upper neighbor is determined by the horizDistance mand vertDistance mresources. This implies some things about how the order of creation affects the possible placement of the children. The Form widget registers a string to widget converter which does not postpone conversion and does not cache conversion results. The second layout method is used when the Dialog is resized. It does not matter what causes this resize, and it is possi- ble for a resize to happen before the widget becomes visible (due to constraints imposed by the parent of the Dialog). This layout method uses the bottom , top , left , and right resources. These resources are used to determine what will happen to each edge of the child when the Dialog is resized. If a value of XawChain <something> is specified, the the edge of the child will remain a fixed distance from the chain edge of the Dialog. For example if XawChainLeft mis specified for the right mresource of a child then the right edge of that child will remain a fixed distance from the left edge of the Dialog widget. If a value of XawRubber mis spec- ified, that edge will grow by the same percentage that the Dialog grew. For instance if the Dialog grows by 50% the left edge of the child (if specified as XawRubber mwill be 50% farther from the left edge of the Dialog). One must be very careful when specifying these resources, for when they are specified incorrectly children may overlap or completely occlude other children when the Dialog widget is resized. Edge Type Resource Name Description XawChainBottom ChainBottom Edge remains a fixed distance from bottom of Dialog XawChainLeft ChainLeft Edge remains a fixed distance from left of Dialog XawChainRight ChainRight Edge remains a fixed distance from right of Dialog XawChainTop ChainTop Edge remains a fixed distance from top of Dialog XawRubber Rubber Edges will move a proportional distance Example If you wish to force the Dialog to never resize one or more of its children then set left and right to XawChainLeft and top and bottom to XawChainTop. This will cause the child to remain a fixed distance from the top and left edges of the Dialog, and to never resize. Special Considerations The Dialog widget automatically sets the top and bottom resources for all Children that are subclasses of the Command widget, as well as the widget children that are used to contain the label, value, and icon. This policy allows the buttons at the bottom of the Dialog to interact correctly with the predefined children, and makes it possible for a client to simply create and manage a new Command button without having to specify its constraints. The Dialog will also set fromLeft to the last button in the Dialog for each new button added to the Dialog widget. The automatically added constraints cannot be overridden, as they are policy decisions of the Dialog widget. If a more flexible Dialog is desired, the application is free to use the Form widget to create its own Dialog policy. Automatically Created Children. The Dialog uses Label widgets to contain the label and icon. These widgets are named label and icon respectively. The Dialog value is contained in an AsciiText widget whose name is value. Using XtNameToWidget the application can change those resources associated with each of these widgets that are not available through the Dialog widget itself. Convenience Routines To return the character string in the text field, use String XawDialogGetValueString Widget w w Specifies the Dialog widget. This function returns a copy of the value string of the Dialog widget. This string is allocated by the AsciiText widget and will remain valid and unchanged until another call to or an call on the value widget, when the string will be automatically freed, and a new string is returned. This string may be freed earlier by calling the function . To add a new button to the Dialog widget use . void XawDialogAddButton Widget w String name XtCallbackProc func XtPointer client_data w Specifies the Dialog widget. name Specifies the name of the new Command button to be added to the Dialog. func Specifies a callback function to be called when this button is activated. If NULL is specified then no callback is added. client_data Specifies the client_data to be passed to the func. This function is merely a shorthand for the code sequence: { Widget button = XtCreateManagedWidget(name, commandWidgetClass, w, NULL, ZERO); XtAddCallback(button, XtNcallback, func, client_data); }