Add documentation for high-level textscreen functions.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 1449

14 files changed, 562 insertions, 19 deletions

diff --git a/textscreen/txt_button.h b/textscreen/txt_button.h
index 11040f2f..ea7fd6e5 100644
--- a/textscreen/txt_button.h
+++ b/textscreen/txt_button.h
@@ -22,6 +22,13 @@
 #ifndef TXT_BUTTON_H
 #define TXT_BUTTON_H
 
+/**
+ * Button widget.
+ *
+ * A button is a widget that can be selected to perform some action.
+ * When a button is pressed, it emits the "pressed" signal.
+ */
+
 typedef struct txt_button_s txt_button_t;
 
 #include "txt_widget.h"
@@ -32,9 +39,35 @@ struct txt_button_s
     char *label;
 };
 
+/**
+ * Create a new button widget.
+ *
+ * @param label        The label to use on the new button.
+ * @return             Pointer to the new button widget.
+ */
+
 txt_button_t *TXT_NewButton(char *label);
-txt_button_t *TXT_NewButton2(char *label, TxtWidgetSignalFunc func, 
+
+/**
+ * Create a new button widget, binding the "pressed" signal to a
+ * specified callback function.
+ *
+ * @param label        The label to use on the new button.
+ * @param func         The callback function to invoke.
+ * @param user_data    User-specified pointer to pass to the callback.
+ * @return             Pointer to the new button widget.
+ */
+
+txt_button_t *TXT_NewButton2(char *label, TxtWidgetSignalFunc func,
                              void *user_data);
+
+/**
+ * Change the label used on a button.
+ *
+ * @param button       The button.
+ * @param label        The new label.
+ */
+
 void TXT_SetButtonLabel(txt_button_t *button, char *label);
 
 #endif /* #ifndef TXT_BUTTON_H */
diff --git a/textscreen/txt_checkbox.h b/textscreen/txt_checkbox.h
index 1b34c3a0..b786ad61 100644
--- a/textscreen/txt_checkbox.h
+++ b/textscreen/txt_checkbox.h
@@ -22,6 +22,19 @@
 #ifndef TXT_CHECKBOX_H
 #define TXT_CHECKBOX_H
 
+/**
+ * Checkbox widget.
+ *
+ * A checkbox is used to control boolean values that may be either on
+ * or off.  The widget has a label that is displayed to the right of
+ * the checkbox indicator.  The widget tracks an integer variable;
+ * if the variable is non-zero, the checkbox is checked, while if it
+ * is zero, the checkbox is unchecked.  It is also possible to
+ * create "inverted" checkboxes where this logic is reversed.
+ *
+ * When a checkbox is changed, it emits the "changed" signal.
+ */
+
 typedef struct txt_checkbox_s txt_checkbox_t;
 
 #include "txt_widget.h"
@@ -34,7 +47,29 @@ struct txt_checkbox_s
     int inverted;
 };
 
+/**
+ * Create a new checkbox.
+ *
+ * @param label         The label for the new checkbox.
+ * @param variable      Pointer to the variable containing this checkbox's
+ *                      value.
+ * @return              Pointer to the new checkbox.
+ */
+
 txt_checkbox_t *TXT_NewCheckBox(char *label, int *variable);
+
+/**
+ * Create a new inverted checkbox.
+ *
+ * An inverted checkbox displays the opposite of a normal checkbox;
+ * where it would be checked, it appears unchecked, and vice-versa.
+ *
+ * @param label         The label for the new checkbox.
+ * @param variable      Pointer to the variable containing this checkbox's
+ *                      value.
+ * @return              Pointer to the new checkbox.
+ */
+
 txt_checkbox_t *TXT_NewInvertedCheckBox(char *label, int *variable);
 
 #endif /* #ifndef TXT_CHECKBOX_H */
diff --git a/textscreen/txt_dropdown.h b/textscreen/txt_dropdown.h
index 1a142b73..6eb8a726 100644
--- a/textscreen/txt_dropdown.h
+++ b/textscreen/txt_dropdown.h
@@ -22,6 +22,16 @@
 #ifndef TXT_DROPDOWN_H
 #define TXT_DROPDOWN_H
 
+/**
+ * Dropdown list widget.
+ *
+ * A dropdown list allows the user to select from a list of values,
+ * which appears when the list is selected.
+ *
+ * When the value of a dropdown list is changed, the "changed" signal
+ * is emitted.
+ */
+
 typedef struct txt_dropdown_list_s txt_dropdown_list_t;
 
 #include "txt_widget.h"
@@ -38,6 +48,20 @@ struct txt_dropdown_list_s
     int num_values;
 };
 
+/**
+ * Create a new dropdown list widget.
+ *
+ * The parameters specify a list of string labels, and a pointer to an
+ * integer variable.  The variable contains the current "value" of the
+ * list, as an index within the list of labels.
+ *
+ * @param variable        Pointer to the variable containing the
+ *                        list's value.
+ * @param values          Pointer to an array of strings containing
+ *                        the labels to use for the list.
+ * @param num_values      The number of variables in the list.
+ */
+
 txt_dropdown_list_t *TXT_NewDropdownList(int *variable, 
                                          char **values, int num_values);
 
diff --git a/textscreen/txt_inputbox.h b/textscreen/txt_inputbox.h
index fa610485..729dbbc6 100644
--- a/textscreen/txt_inputbox.h
+++ b/textscreen/txt_inputbox.h
@@ -22,6 +22,15 @@
 #ifndef TXT_INPUTBOX_H
 #define TXT_INPUTBOX_H
 
+/**
+ * Input box widget.
+ *
+ * An input box is a widget that displays a value, which can be
+ * selected to enter a new value.
+ *
+ * Input box widgets can be of an integer or string type.
+ */
+
 typedef struct txt_inputbox_s txt_inputbox_t;
 
 #include "txt_widget.h"
@@ -35,7 +44,30 @@ struct txt_inputbox_s
     void *value;
 };
 
+/**
+ * Create a new input box widget for controlling a string value.
+ *
+ * @param value         Pointer to a string variable that contains
+ *                      a pointer to the current value of the
+ *                      input box.  The value should be allocated
+ *                      dynamically; when the string is changed it
+ *                      will be freed and the variable set to point
+ *                      to the new string value.
+ * @param size          Width of the input box, in characters.
+ * @return              Pointer to the new input box widget.
+ */
+
 txt_inputbox_t *TXT_NewInputBox(char **value, int size);
+
+/**
+ * Create a new input box widget for controlling an integer value.
+ *
+ * @param value         Pointer to an integer variable containing
+ *                      the value of the input box.
+ * @param size          Width of the input box, in characters.
+ * @return              Pointer to the new input box widget.
+ */
+
 txt_inputbox_t *TXT_NewIntInputBox(int *value, int size);
 
 #endif /* #ifndef TXT_INPUTBOX_H */
diff --git a/textscreen/txt_label.h b/textscreen/txt_label.h
index c8e002e0..ba1b0c3e 100644
--- a/textscreen/txt_label.h
+++ b/textscreen/txt_label.h
@@ -22,6 +22,12 @@
 #ifndef TXT_LABEL_H
 #define TXT_LABEL_H
 
+/**
+ * Label widget.
+ *
+ * A label widget does nothing except show a text label.
+ */
+
 typedef struct txt_label_s txt_label_t;
 
 #include "txt_main.h"
@@ -37,9 +43,40 @@ struct txt_label_s
     txt_color_t bgcolor;
 };
 
+/**
+ * Create a new label widget.
+ *
+ * @param label         String to display in the widget.
+ * @return              Pointer to the new label widget.
+ */
+
 txt_label_t *TXT_NewLabel(char *label);
+
+/**
+ * Set the string displayed in a label widget.
+ *
+ * @param label         The widget.
+ * @param value         The string to display.
+ */
+
 void TXT_SetLabel(txt_label_t *label, char *value);
+
+/**
+ * Set the background color of a label widget.
+ *
+ * @param label         The widget.
+ * @param color         The background color to use.
+ */
+
 void TXT_SetBGColor(txt_label_t *label, txt_color_t color);
+
+/**
+ * Set the foreground color of a label widget.
+ *
+ * @param label         The widget.
+ * @param color         The foreground color to use.
+ */
+
 void TXT_SetFGColor(txt_label_t *label, txt_color_t color);
 
 #endif /* #ifndef TXT_LABEL_H */
diff --git a/textscreen/txt_radiobutton.h b/textscreen/txt_radiobutton.h
index d668254c..b1d6487c 100644
--- a/textscreen/txt_radiobutton.h
+++ b/textscreen/txt_radiobutton.h
@@ -22,6 +22,24 @@
 #ifndef TXT_RADIOBUTTON_H
 #define TXT_RADIOBUTTON_H
 
+/**
+ * A radio button widget.
+ *
+ * Radio buttons are typically used in groups, to allow a value to be
+ * selected from a range of options.  Each radio button corresponds
+ * to a particular option that may be selected.  A radio button
+ * has an indicator to indicate whether it is the currently-selected
+ * value, and a text label.
+ *
+ * Internally, a radio button tracks an integer variable that may take
+ * a range of different values.  Each radio button has a particular
+ * value associated with it; if the variable is equal to that value,
+ * the radio button appears selected.  If a radio button is pressed
+ * by the user through the GUI, the variable is set to its value.
+ *
+ * When a radio button is selected, the "selected" signal is emitted.
+ */
+
 typedef struct txt_radiobutton_s txt_radiobutton_t;
 
 #include "txt_widget.h"
@@ -34,7 +52,26 @@ struct txt_radiobutton_s
     int value;
 };
 
+/**
+ * Create a new radio button widget.
+ *
+ * @param label          The label to display next to the radio button.
+ * @param variable       Pointer to the variable tracking whether this
+ *                       radio button is selected.
+ * @param value          If the variable is equal to this value, the
+ *                       radio button appears selected.
+ * @return               Pointer to the new radio button widget.
+ */
+
 txt_radiobutton_t *TXT_NewRadioButton(char *label, int *variable, int value);
+
+/**
+ * Set the label on a radio button.
+ *
+ * @param radiobutton    The radio button.
+ * @param value          The new label.
+ */
+
 void TXT_SetRadioButtonLabel(txt_radiobutton_t *radiobutton, char *value);
 
 #endif /* #ifndef TXT_RADIOBUTTON_H */
diff --git a/textscreen/txt_scrollpane.h b/textscreen/txt_scrollpane.h
index 661542a3..7242e61e 100644
--- a/textscreen/txt_scrollpane.h
+++ b/textscreen/txt_scrollpane.h
@@ -22,6 +22,14 @@
 #ifndef TXT_SCROLLPANE_H
 #define TXT_SCROLLPANE_H
 
+/**
+ * Scrollable pane widget.
+ *
+ * A scrollable pane widget is a widget that contains another widget
+ * that is larger than it.  Scroll bars appear on the side to allow
+ * different areas of the contained widget to be seen.
+ */
+
 typedef struct txt_scrollpane_s txt_scrollpane_t;
 
 #include "txt_widget.h"
@@ -35,6 +43,16 @@ struct txt_scrollpane_s
     txt_widget_t *child;
 };
 
+/**
+ * Create a new scroll pane widget.
+ *
+ * @param w               Width of the scroll pane, in characters.
+ * @param h               Height of the scroll pane, in lines.
+ * @param target          The target widget that the scroll pane will
+ *                        contain.
+ * @return                Pointer to the new scroll pane widget.
+ */
+
 txt_scrollpane_t *TXT_NewScrollPane(int w, int h, TXT_UNCAST_ARG(target));
 
 #endif /* #ifndef TXT_SCROLLPANE_H */
diff --git a/textscreen/txt_separator.h b/textscreen/txt_separator.h
index c8691171..518a56c9 100644
--- a/textscreen/txt_separator.h
+++ b/textscreen/txt_separator.h
@@ -22,6 +22,15 @@
 #ifndef TXT_SEPARATOR_H
 #define TXT_SEPARATOR_H
 
+/**
+ * Horizontal separator.
+ *
+ * A horizontal separator appears as a horizontal line divider across
+ * the length of the window in which it is added.  An optional label
+ * allows the separator to be used as a section divider for grouping
+ * related controls.
+ */
+
 typedef struct txt_separator_s txt_separator_t;
 
 #include "txt_widget.h"
@@ -34,6 +43,14 @@ struct txt_separator_s
 
 extern txt_widget_class_t txt_separator_class;
 
+/**
+ * Create a new horizontal separator widget.
+ *
+ * @param label         Label to display on the separator.  If this is
+ *                      set to NULL, no label is displayed.
+ * @return              The new separator widget.
+ */
+
 txt_separator_t *TXT_NewSeparator(char *label);
 
 #endif /* #ifndef TXT_SEPARATOR_H */
diff --git a/textscreen/txt_spinctrl.h b/textscreen/txt_spinctrl.h
index 2fdd2a62..02d5a211 100644
--- a/textscreen/txt_spinctrl.h
+++ b/textscreen/txt_spinctrl.h
@@ -22,7 +22,16 @@
 #ifndef TXT_SPINCONTROL_H
 #define TXT_SPINCONTROL_H
 
+/**
+ * Spin control widget.
+ *
+ * A spin control widget works as an input box that can be used to
+ * set numeric values, but also has buttons that allow its value
+ * to be increased or decreased.
+ */
+
 typedef struct txt_spincontrol_s txt_spincontrol_t;
+
 typedef enum
 {
     TXT_SPINCONTROL_INT,
@@ -40,7 +49,28 @@ struct txt_spincontrol_s
     char *buffer;
 };
 
+/**
+ * Create a new spin control widget tracking an integer value.
+ *
+ * @param value        Pointer to the variable containing the value
+ *                     displayed in the widget.
+ * @param min          Minimum value that may be set.
+ * @param max          Maximum value that may be set.
+ * @return             Pointer to the new spin control widget.
+ */
+
 txt_spincontrol_t *TXT_NewSpinControl(int *value, int min, int max);
+
+/**
+ * Create a new spin control widget tracking a float value.
+ *
+ * @param value        Pointer to the variable containing the value
+ *                     displayed in the widget.
+ * @param min          Minimum value that may be set.
+ * @param max          Maximum value that may be set.
+ * @return             Pointer to the new spin control widget.
+ */
+
 txt_spincontrol_t *TXT_NewFloatSpinControl(float *value, float min, float max);
 
 #endif /* #ifndef TXT_SPINCONTROL_H */
diff --git a/textscreen/txt_strut.h b/textscreen/txt_strut.h
index 7d9e7650..8436aa9c 100644
--- a/textscreen/txt_strut.h
+++ b/textscreen/txt_strut.h
@@ -22,15 +22,18 @@
 #ifndef TXT_STRUT_H
 #define TXT_STRUT_H
 
+/**
+ * Strut widget.
+ *
+ * A strut is a widget that takes up a fixed amount of space.  It can
+ * be visualised as a transparent box.  Struts are used to provide
+ * spacing between widgets.
+ */
+
 typedef struct txt_strut_s txt_strut_t;
 
 #include "txt_widget.h"
 
-//
-// A strut is used to force a table to a minimum width/height.  It is not
-// visible but it takes up space.
-// 
-
 struct txt_strut_s
 {
     txt_widget_t widget;
@@ -38,6 +41,13 @@ struct txt_strut_s
     int height;
 };
 
+/**
+ * Create a new strut.
+ *
+ * @param width      Width of the strut, in characters.
+ * @param height     Height of the strut, in characters.
+ */
+
 txt_strut_t *TXT_NewStrut(int width, int height);
 
 #endif /* #ifndef TXT_STRUT_H */
diff --git a/textscreen/txt_table.h b/textscreen/txt_table.h
index dee6f4bb..2bbb8ffc 100644
--- a/textscreen/txt_table.h
+++ b/textscreen/txt_table.h
@@ -22,9 +22,23 @@
 #ifndef TXT_TABLE_H
 #define TXT_TABLE_H
 
+/**
+ * Table widget.
+ *
+ * A table is a widget that contains other widgets.  It may have
+ * multiple columns, in which case the child widgets are laid out
+ * in a grid.  Columns automatically grow as necessary, although
+ * minimum column widths can be set using @ref TXT_SetColumnWidths.
+ *
+ * To create a new table, use @ref TXT_NewTable.  It is also
+ * possible to use @ref TXT_NewHorizBox to create a table, specifying
+ * widgets to place inside a horizontal list.  A vertical list is
+ * possible simply by creating a table containing a single column.
+ */
+
 typedef struct txt_table_s txt_table_t;
 
-#include "txt_widget.h" 
+#include "txt_widget.h"
 
 struct txt_table_s
 {
@@ -48,14 +62,114 @@ struct txt_table_s
 
 extern txt_widget_class_t txt_table_class;
 
+void TXT_InitTable(txt_table_t *table, int columns);
+
+/**
+ * Create a new table.
+ *
+ * @param columns       The number of columns in the new table.
+ * @return              Pointer to the new table structure.
+ */
+
 txt_table_t *TXT_NewTable(int columns);
+
+/**
+ * Create a table containing the specified widgets packed horizontally,
+ * from left to right.
+ *
+ * The arguments to this function are variable.  Each argument must
+ * be a pointer to a widget, and the list is terminated with a
+ * NULL.
+ *
+ * @return             Pointer to the new table structure.
+ */
+
 txt_table_t *TXT_NewHorizBox(TXT_UNCAST_ARG(first_widget), ...);
-void TXT_InitTable(txt_table_t *table, int columns);
+
+/**
+ * Get the currently selected widget within a table.
+ *
+ * This function will recurse through subtables if necessary.
+ *
+ * @param table        The table.
+ * @return             Pointer to the widget that is currently selected.
+ */
+
 txt_widget_t *TXT_GetSelectedWidget(TXT_UNCAST_ARG(table));
+
+/**
+ * Add a widget to a table.
+ *
+ * Widgets are added to tables horizontally, from left to right.
+ * For example, for a table with three columns, the first call
+ * to this function will add a widget to the first column, the second
+ * call to the second column, the third call to the third column,
+ * and the fourth will return to the first column, starting a new
+ * row.
+ *
+ * For adding many widgets, it may be easier to use
+ * @ref TXT_AddWidgets.
+ *
+ * @param table        The table.
+ * @param widget       The widget to add.
+ */
+
 void TXT_AddWidget(TXT_UNCAST_ARG(table), TXT_UNCAST_ARG(widget));
+
+/**
+ * Add multiple widgets to a table.
+ *
+ * Widgets are added as described in the documentation for the
+ * @ref TXT_AddWidget function.  This function adds multiple
+ * widgets.  The number of arguments is variable, and the argument
+ * list must be terminated by a NULL pointer.
+ *
+ * @param table        The table.
+ */
+
 void TXT_AddWidgets(TXT_UNCAST_ARG(table), ...);
+
+/**
+ * Select the given widget that is contained within the specified
+ * table.
+ *
+ * This function will recursively search through subtables if
+ * necessary.
+ *
+ * @param table       The table.
+ * @param widget      The widget to select.
+ * @return            Non-zero (true) if it has been selected,
+ *                    or zero (false) if it was not found within
+ *                    this table.
+ */
+
 int TXT_SelectWidget(TXT_UNCAST_ARG(table), TXT_UNCAST_ARG(widget));
+
+/**
+ * Set the widths of the columns of the table.
+ *
+ * The arguments to this function are variable, and correspond
+ * to the number of columns in the table.  For example, if a table
+ * has five columns, the width of each of the five columns must be
+ * specified.
+ *
+ * The width values are in number of characters.
+ *
+ * Note that this function only sets the minimum widths for columns;
+ * if the columns contain widgets that are wider than the widths
+ * specified, they will be larger.
+ *
+ * @param table     The table.
+ */
+
 void TXT_SetColumnWidths(TXT_UNCAST_ARG(table), ...);
+
+/**
+ * Remove all widgets from a table.
+ *
+ * @param table    The table.
+ */
+
 void TXT_ClearTable(TXT_UNCAST_ARG(table));
 
 #endif /* #ifndef TXT_TABLE_T */
diff --git a/textscreen/txt_widget.h b/textscreen/txt_widget.h
index 0e80f3c1..b1afea50 100644
--- a/textscreen/txt_widget.h
+++ b/textscreen/txt_widget.h
@@ -42,8 +42,20 @@ typedef enum
     TXT_HORIZ_RIGHT,
 } txt_horiz_align_t;
 
-typedef struct txt_widget_class_s txt_widget_class_t;
+/**
+ * A GUI widget.
+ *
+ * A widget is an individual component of a GUI.  Various different widget
+ * types exist.
+ *
+ * Widgets may emit signals.  The types of signal emitted by a widget
+ * depend on the type of the widget.  It is possible to be notified
+ * when a signal occurs using the @ref TXT_SignalConnect function.
+ */
+
 typedef struct txt_widget_s txt_widget_t;
+
+typedef struct txt_widget_class_s txt_widget_class_t;
 typedef struct txt_callback_table_s txt_callback_table_t;
 
 typedef void (*TxtWidgetSizeCalc)(TXT_UNCAST_ARG(widget));
@@ -82,15 +94,34 @@ struct txt_widget_s
 void TXT_InitWidget(TXT_UNCAST_ARG(widget), txt_widget_class_t *widget_class);
 void TXT_CalcWidgetSize(TXT_UNCAST_ARG(widget));
 void TXT_DrawWidget(TXT_UNCAST_ARG(widget), int selected);
-void TXT_SignalConnect(TXT_UNCAST_ARG(widget), char *signal_name,
-                       TxtWidgetSignalFunc func, void *user_data);
 void TXT_EmitSignal(TXT_UNCAST_ARG(widget), char *signal_name);
 int TXT_WidgetKeyPress(TXT_UNCAST_ARG(widget), int key);
 void TXT_WidgetMousePress(TXT_UNCAST_ARG(widget), int x, int y, int b);
 void TXT_DestroyWidget(TXT_UNCAST_ARG(widget));
-void TXT_SetWidgetAlign(TXT_UNCAST_ARG(widget), txt_horiz_align_t horiz_align);
 void TXT_LayoutWidget(TXT_UNCAST_ARG(widget));
 
+/**
+ * Set a callback function to be invoked when a signal occurs.
+ *
+ * @param widget       The widget to watch.
+ * @param signal_name  The signal to watch.
+ * @param func         The callback function to invoke.
+ * @param user_data    User-specified pointer to pass to the callback function.
+ */
+
+void TXT_SignalConnect(TXT_UNCAST_ARG(widget), char *signal_name,
+                       TxtWidgetSignalFunc func, void *user_data);
+
+/**
+ * Set the policy for how a widget should be aligned within a table.
+ * By default, widgets are aligned to the left of the column.
+ *
+ * @param widget       The widget.
+ * @param horiz_align  The alignment to use.
+ */
+
+void TXT_SetWidgetAlign(TXT_UNCAST_ARG(widget), txt_horiz_align_t horiz_align);
+
 #endif /* #ifndef TXT_WIDGET_H */
 
 
diff --git a/textscreen/txt_window.h b/textscreen/txt_window.h
index 3659ed29..38c7a128 100644
--- a/textscreen/txt_window.h
+++ b/textscreen/txt_window.h
@@ -22,6 +22,25 @@
 #ifndef TXT_WINDOW_H
 #define TXT_WINDOW_H
 
+/**
+ * A window.
+ *
+ * A window contains widgets, and may also be treated as a table
+ * containing a single column.
+ *
+ * Windows can be created using @ref TXT_NewWindow and closed using
+ * @ref TXT_CloseWindow.  When a window is closed, it emits the
+ * "closed" signal.
+ *
+ * In addition to the widgets within a window, windows also have
+ * a "tray" area at their bottom containing window action widgets.
+ * These widgets allow keyboard shortcuts to trigger common actions.
+ * Each window has three slots for keyboard shortcuts. By default,
+ * the left slot contains an action to close the window when the
+ * escape button is pressed, while the right slot contains an
+ * action to activate the currently-selected widget.
+ */
+
 typedef struct txt_window_s txt_window_t;
 
 #include "txt_widget.h" 
@@ -68,18 +87,86 @@ struct txt_window_s
     unsigned int window_w, window_h;
 };
 
+/**
+ * Open a new window.
+ *
+ * @param title        Title to display in the titlebar of the new window.
+ * @return             Pointer to a new @ref txt_window_t structure
+ *                     representing the new window.
+ */
+
 txt_window_t *TXT_NewWindow(char *title);
+
+/**
+ * Close a window.
+ *
+ * @param window       Tine window to close.
+ */
+
 void TXT_CloseWindow(txt_window_t *window);
-void TXT_SetWindowPosition(txt_window_t *window, 
+
+/**
+ * Set the position of a window on the screen.
+ *
+ * The window is specified as coordinates relative to a predefined
+ * position on the screen (eg. center of the screen, top left of the
+ * screen, etc).
+ *
+ * @param window       The window.
+ * @param horiz_align  Horizontal position on the screen to which the
+ *                     coordinates are relative (left side, right side
+ *                     or center).
+ * @param vert_align   Vertical position on the screen to which the
+ *                     coordinates are relative (top, bottom or center).
+ * @param x            X coordinate (horizonal axis) for window position.
+ * @param y            Y coordinate (vertical axis) for window position.
+ */
+
+void TXT_SetWindowPosition(txt_window_t *window,
                            txt_horiz_align_t horiz_align,
                            txt_vert_align_t vert_align,
                            int x, int y);
+
+/**
+ * Set a window action for a given window.
+ *
+ * Each window can have up to three window actions, which provide
+ * keyboard shortcuts that can be used within a given window.
+ *
+ * @param window      The window.
+ * @param position    The window action slot to set (left, center or right).
+ * @param action      The window action widget.  If this is NULL, any
+ *                    current window action in the given slot is removed.
+ */
+
 void TXT_SetWindowAction(txt_window_t *window, txt_horiz_align_t position, 
                          txt_window_action_t *action);
-void TXT_SetKeyListener(txt_window_t *window, 
-                        TxtWindowKeyPress key_listener, 
+
+/**
+ * Set a callback function to be invoked whenever a key is pressed within
+ * a window.
+ *
+ * @param window        The window.
+ * @param key_listener  Callback function.
+ * @param user_data     User-specified pointer to pass to the callback
+ *                      function.
+ */
+
+void TXT_SetKeyListener(txt_window_t *window,
+                        TxtWindowKeyPress key_listener,
                         void *user_data);
-void TXT_SetMouseListener(txt_window_t *window, 
+
+/**
+ * Set a callback function to be invoked whenever a mouse button is pressed
+ * within a window.
+ *
+ * @param window          The window.
+ * @param mouse_listener  Callback function.
+ * @param user_data       User-specified pointer to pass to the callback
+ *                        function.
+ */
+
+void TXT_SetMouseListener(txt_window_t *window,
                           TxtWindowMousePress mouse_listener,
                           void *user_data);
 
diff --git a/textscreen/txt_window_action.h b/textscreen/txt_window_action.h
index 56f5a1b6..3f016bdb 100644
--- a/textscreen/txt_window_action.h
+++ b/textscreen/txt_window_action.h
@@ -22,6 +22,16 @@
 #ifndef TXT_WINDOW_ACTION_H
 #define TXT_WINDOW_ACTION_H
 
+/**
+ * Window action widget.
+ *
+ * A window action is attached to a window and corresponds to a
+ * keyboard shortcut that is active within that window.  When the
+ * key is pressed, the action is triggered.
+ *
+ * When a window action is triggered, the "pressed" signal is emitted.
+ */
+
 typedef struct txt_window_action_s txt_window_action_t;
 
 #include "txt_widget.h"
@@ -34,17 +44,45 @@ struct txt_window_action_s
     int key;
 };
 
+/**
+ * Create a new window action.
+ *
+ * @param key           The keyboard key that triggers this action.
+ * @param label         Label to display for this action in the tray
+ *                      at the bottom of the window.
+ * @return              Pointer to the new window action widget.
+ */
+
 txt_window_action_t *TXT_NewWindowAction(int key, char *label);
 
-// Creates an "escape" button that closes the window
+/**
+ * Create a new window action that closes the window when the
+ * escape key is pressed.  The label "Close" is used.
+ *
+ * @param window        The window to close.
+ * @return              Pointer to the new window action widget.
+ */
 
 txt_window_action_t *TXT_NewWindowEscapeAction(txt_window_t *window);
 
-// Same as above, but the button is named "abort"
+/**
+ * Create a new window action that closes the window when the
+ * escape key is pressed.  The label "Abort" is used.
+ *
+ * @param window        The window to close.
+ * @return              Pointer to the new window action widget.
+ */
 
 txt_window_action_t *TXT_NewWindowAbortAction(txt_window_t *window);
 
-// Accept button that does nothing
+/**
+ * Create a new "select" window action.  This does not really do
+ * anything, but reminds the user that "enter" can be pressed to
+ * activate the currently-selected widget.
+ *
+ * @param window        The window.
+ * @return              Pointer to the new window action widget.
+ */
 
 txt_window_action_t *TXT_NewWindowSelectAction(txt_window_t *window);