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Window Classes:
Window classes define the behavior of windows. Each class has its own
unique reaction to messages. Classes derive from other classes.
NORMAL base window for all window classes
APPLICATION application window. has the menu
(derived from NORMAL)
TEXTBOX textbox. base window for listbox, editbox, etc.
(derived from NORMAL)
LISTBOX listbox. base window for menubar
(derived from TEXTBOX)
EDITBOX editbox
(derived from TEXTBOX)
MENUBAR the application's menu bar
(derived from NORMAL)
POPDOWNMENU popdown menu
(derived from LISTBOX)
BUTTON command button in a dialog box
(derived from TEXTBOX)
DIALOG dialog box. parent to editbox, button, listbox, etc.
(derived from NORMAL)
ERRORBOX for displaying an error message
(derived from DIALOG)
MESSAGEBOX for displaying a message
(derived from DIALOG)
HELPBOX help window
(derived from DIALOG)
TEXT static text on a dialog box
RADIOBUTTON radio button on a dialog box
CHECKBOX check box on a dialog box
STATUSBAR status bar at the bottom of application window
D-Flat Window Class Tree
┌─────────────────────────────────────────────┐
│ │
│ NORMAL │
│ │ │
│ ├── APPLICATION │
│ │ │
│ ├── MENUBAR │
│ │ │
│ ├── TEXTBOX │
│ │ │ │
│ │ ├── LISTBOX │
│ │ │ │ │
│ │ │ └──── POPDOWNMENU │
│ │ │ │
│ │ ├── EDITBOX │
│ │ │ │
│ │ ├── STATUSBAR │
│ │ │ │
│ │ └── BUTTON │
│ │ │
│ └── DIALOG │
│ │ │
│ ├── ERRORBOX │
│ │ │
│ ├── MESSAGEBOX │
│ │ │
│ └── HELPBOX │
│ │
└─────────────────────────────────────────────┘
Window Attributes:
Every window has an attribute word that defines some of its
appearance and behavior. The following values are bitwise flags that
OR together to make a window's attributes.
You can establish default attributes for a window's class, add
additional attributes when you create the window, and use the
AddAttribute, ClearAttribute, and TestAttribute macros to change and
test a window's attributes.
SHADOW has a shadow
MOVEABLE can move the window with mouse or cursor
SIZEABLE can resize the window with mouse or cursor
HASMENUBAR has a menubar (an application window)
VSCROLLBAR has a vertical scroll bar
HSCROLLBAR has a horizontal scroll bar
VISIBLE is visible
SAVESELF saves its own video memory
TITLEBAR has a title bar
CONTROLBOX has a control box and control menu
MINMAXBOX has a min/max box
NOCLIP is not clipped to its parent's borders
READONLY is a readonly textbox
MULTILINE is a multiline editbox or listbox
HASBORDER has a border
HASSTATUSBAR has a statusbar (application window only)
Messages:
A D-Flat program is message-driven. You initiate message processing
with the init_messages function, create a window with the
CreateWindow function, and go into the message dispatching loop with
the dispatch_message function.
A window can have a window-processing function. When the user causes
events to occur by pressing keys and using the mouse, D-Flat sends
messages to the window's function. That function can send messages to
itself and other windows with the SendMessage and PostMessage
functions.
Windows are declared as members of a class. Every class has a default
window-processing function. If you do not provide one for an instance
of a window class, the default one receives messages for the window.
Your custom window-processing function--if one exists--should chain to
the default window-processing function for the blass by calling the
DefaultWndProc function.
There are five things a window-processing function can do with a
message:
- ignore it and let the D-Flat default processing occur.
- suppress it by returning without chaining to the default
window-processing function for the window class.
- chain to the default window-processing function and then do some
additional processing.
- do some preliminary processing and then chain to the default
window-processing function.
- do all the processing of the message and then return without
chaining to the default window-processing function for the
window class.
Following are the messages that an application program would use.
There are other messages, but they are used by D-Flat only.
Process Communication Messages
START start message processing (not used now)
Sent:
P1:
P2:
Returns:
STOP stop message processing
Sent: by application window to NULLWND to stop message
dispatch loop
P1:
P2:
Returns:
COMMAND send a command to a window
Sent: to send command
P1: command code (commands.h)
P2: additional data (command-dependent)
Returns: Nothing if sent by PostCommand
Command-dependent value if sent by SendCommand
Window Management Messages
CREATE_WINDOW create a window
Sent: by DFLAT to new window after window is created
P1:
P2:
Returns:
SHOW_WINDOW show a window
Sent: by the app to the window to display the window
P1:
P2:
Returns:
HIDE_WINDOW hide a window
Sent: by the app to the window to hide the window
P1:
P2:
Returns:
CLOSE_WINDOW delete a window
Sent: by the app to destroy a window
P1:
P2:
Returns:
SETFOCUS set and clear the focus
Sent: by D-Flat or the app to set or release the focus
P1: true = set, false = release
P2:
Returns:
PAINT paint the window's data space
Sent: to paint the client area of a window
P1: RECT relative to window (0/0 = upper left) to paint
or 0 to paint entire client area
P2:
Returns:
BORDER paint the window's border
Sent: to paint a window's border
P1: RECT relative to window (0/0 = upper left) to paint
or 0 to paint entire border
P2:
Returns: FALSE to suppress D-Flat title display
(e.g. the window displays its own border)
TITLE display the window's title
Sent: by D-Flat when it is about to display a window's title
P1: RECT relative to window (0/0 = upper left) to paint
or 0 to paint entire title
P2:
Returns: FALSE to suppress D-Flat title display
(e.g. the window displays its own title)
MOVE move the window
Sent: to move a window
P1: new left coordinate
P2: new upper coordinate
Returns:
SIZE change the window's size
Sent: to resize a window
P1: new right coordinate
P2: new lower coordinate
Returns:
MAXIMIZE maximize the window
Sent: to maximize a window within its parent's client area
P1:
P2:
Returns:
MINIMIZE minimize the window
Sent: to minimize a window to an icon
P1:
P2:
Returns:
RESTORE restore the window
Sent: to restore a window to its position and size prior to the
maximize or minimize operation
P1:
P2:
Returns:
INSIDE_WINDOW test x/y inside a window
Sent: to test to see if coordinates are inside a window
P1: x
P2: y
Returns: true or false
Clock Messages
CLOCKTICK the clock ticked
Sent: every second to a window that has captured the clock
P1: segment of time display string
P2: offset of time display string
Returns:
CAPTURE_CLOCK capture clock into a window
Sent: to capture the clock
P1:
P2:
Returns:
RELEASE_CLOCK release clock to the system
Sent: to release the captured clock
P1:
P2:
Returns:
Keyboard and Screen Messages
KEYBOARD key was pressed
Sent: when key is pressed. sent to the window that has the focus
P1: keystroke
P2: shift key mask
Returns:
CAPTURE_KEYBOARD capture keyboard into a window
Sent: by window to itself to capture the keyboard
regardless of focus
P1:
P2:
Returns:
RELEASE_KEYBOARD release keyboard to system
Sent: by window to itelf to release the captured keyboard
P1:
P2:
Returns:
KEYBOARD_CURSOR position the keyboard cursor
Sent: to position the keyboard cursor
P1: x (if sent by window, 0 = left client area)
P2: y (if sent by window, 0 = top client area)
if sent with NULLWND, x/y are relative to the screen
Returns:
CURRENT_KEYBOARD_CURSOR read the cursor position
Sent: to retrieve the cursor position
P1: x (relative to the screen)
P2: y (relative to the screen)
Returns:
HIDE_CURSOR hide the keyboard cursor
Sent: to hide the keyboard cursor
P1:
P2:
Returns:
SHOW_CURSOR display the keyboard cursor
Sent: to display the keyboard cursor
P1:
P2:
Returns:
SAVE_CURSOR save the cursor's configuration
Sent: to save the keyboard cursor's current configuration
P1:
P2:
Returns:
RESTORE_CURSOR restore the saved cursor
Sent: to restore a keyboard cursor's saved configuration
P1:
P2:
Returns:
SHIFT_CHANGED the shift status changed
Sent: to in-focus window when the user presses or
releases shift, alt, or ctrl key
P1: BIOS shift key mask
P2:
Returns:
WAITKEYBOARD wait for key release
Sent: to wait for a keypress release
P1:
P2:
Returns:
Mouse Messages
MOUSE_INSTALLED test for mouse installed
Sent: to see if the mouse is installed
P1:
P2:
Returns: true or false
RIGHT_BUTTON right button pressed
Sent: to window when the user presses the right button
(sent only when mouse cursor is within the window
or the window has captured the mouse)
P1: x
P2: y
Returns:
LEFT_BUTTON left button pressed
Sent: to window when the user presses the left button
(sent only when mouse cursor is within the window
or the window has captured the mouse)
P1: x
P2: y
Returns:
DOUBLE_CLICK left button doubleclicked
Sent: to window when the user double-clicks the left button
(sent only when mouse cursor is within the window
or the window has captured the mouse)
(a LEFT_BUTTON message will have preceded this one)
P1: x
P2: y
Returns:
MOUSE_MOVED mouse changed position
Sent: to window when the mouse has moved
(sent only when mouse cursor is within the window
or the window has captured the mouse)
P1: x
P2: y
Returns:
BUTTON_RELEASED mouse button released
Sent: to window when user releases mouse button
(sent only when mouse cursor is within the window
or the window has captured the mouse)
P1: x
P2: y
Returns:
CURRENT_MOUSE_CURSOR get mouse position
Sent: to determine the current mouse position
P1: address of x
P2: address of y
Returns:
MOUSE_CURSOR set mouse position
Sent: to set the current mouse position
P1: x
P2: y
Returns:
SHOW_MOUSE make mouse cursor visible
Sent: to display the mouse cursor
P1:
P2:
Returns:
HIDE_MOUSE hide mouse cursor
Sent: to hide the mouse cursor
P1:
P2:
Returns:
WAITMOUSE wait until button released
Sent: to wait until the user releases the mouse button
P1:
P2:
Returns:
TESTMOUSE test any mouse button pressed
Sent: to see if either mouse button is pressed
P1:
P2:
Returns: true or false
CAPTURE_MOUSE capture mouse into a window
Sent: by/to a window to capture all mouse activity
regardless of whether it occurs inside this window
P1:
P2:
Returns:
RELEASE_MOUSE release the mouse to system
Sent: release a captured mouse
P1:
P2:
Returns:
Text Box Messages
ADDTEXT add text to the text box
Sent: to append a line of text to the text box
P1: address of null-terminated string
(textbox makes its own copy. string can go out of scope.)
P2:
Returns:
CLEARTEXT clear the text box
Sent: clear all text from the text box
P1:
P2:
Returns:
SETTEXT set address of text buffer
Sent: To set text buffer to caller's text.
P1: address of text buffer
(lines are terminated by \n without \0)
(textbox makes its own copy. string can go out of scope.)
P2: length of text buffer
Returns:
SCROLL vertical scroll of text box
Sent: to scroll a text window vertically one line
P1: true = scroll up, false = scroll down
P2:
Returns:
HORIZSCROLL horizontal scroll of text box
Sent: to scroll a text window horizontally one line
P1: true = scroll left
P2: false = scroll right
Returns:
Edit Box Messages
EB_GETTEXT get text from an edit box
Sent: Get the line of text from a single-line editbox
P1: address of receiving buffer
P2: max length to copy
Returns:
EB_PUTTEXT put text into an edit box
Sent: replace old or insert first text into an editbox
P1: address of text (null-terminated string)
P2:
Returns:
Application Window Messages
ADDSTATUS write text to the status bar
Sent: to write to or clear status bar text area
P1: address of text (null-terminated string) or NULL to clear
P2:
Returns:
List Box Messages
LB_SELECTION list box selection
Sent: sent by list box to self and to parent (if parent is not
a simple LISTBOX window) when user moves to an entry on
the list box.
P1: selection number: 0, 1, ...
P2: if multi-line selection listbox, shift status mask
if not, true = selection was same as choice (e.g. mouse)
Returns:
LB_CHOOSE list box choice
Sent: sent to parent of list box when user chooses an item
from the list box
P1: selection number: 0, 1, ...
P2:
Returns:
LB_CURRENTSELECTION return the current selection
Sent: To get the current selection number (where the listbox
cursor is positioned)
P1:
P2:
Returns: selection number: 0, 1, ...
LB_GETTEXT return the text of selection
Sent: To get a copy of the text at a specified line
P1: Address of string to receive copy of text
P2: Line number: 0, 1, ...
Returns:
LB_SETSELECTION sets the listbox selection
Sent: To change where the listbox cursor points
P1: Line number: 0, 1, ...
P2:
Returns:
API Functions & Macros:
These are functions and macros defined for use by applications
programs. There are many others defined in the header files. These
others are for D-Flat to use, and programmers need not be concerned
about them except as an expression of their curiosity about how
D-Flat works.
(Note: These specifications are not in any orderly sequence yet.)
-------------------------------------------------------------------
void init_messages(void)
Call this function first to initialize message processing
-------------------------------------------------------------------
WINDOW CreateWindow(
CLASS class, /* class of this window */
char *ttl, /* title or NULL */
int left, int top, /* upper left coordinates */
int height, int width, /* dimensions */
void *extension, /* pointer to additional data */
WINDOW parent, /* parent of this window */
int (*wndproc)(struct window *,MESSAGE,PARAM,PARAM),
int attrib) /* window attribute */
This function creates a window. It returns the WINDOW handle that
mesages and functions use to identify the window.
-------------------------------------------------------------------
void PostMessage(WINDOW wnd, MESSAGE msg, PARAM p1, PARAM p2)
Post a message to a window. The window will receive the message in
turn during the message-dispatching loop.
-------------------------------------------------------------------
int SendMessage(WINDOW wnd, MESSAGE msg, PARAM p1, PARAM p2)
Send a message to a window. The window will receive the message
immediately. Control returns to the sender after the window has
processed the message. The window can return an integer value.
This function can send system messages to NULLWND. System messages
are ones that D-Flat processes without regard to a particular window.
-------------------------------------------------------------------
int dispatch_message(void)
The message dispatching loop. After opening the first window (usually
the applications window), continue to call this function until it
returns a FALSE value.
-------------------------------------------------------------------
int TestCriticalError(void)
-------------------------------------------------------------------
int DefaultWndProc(WINDOW wnd, MESSAGE msg, PARAM p1, PARAM p2)
Call this from a window-processing function to chain to the default
window-processing function for the window's class.
-------------------------------------------------------------------
int BaseWndProc(CLASS class, WINDOW wnd, MESSAGE msg, PARAM p1, PARAM p2)
Call this from the window-processing function of a derived window
class to chain to the window-processing function of the base window's
class.
-------------------------------------------------------------------
int WindowHeight(WINDOW wnd)
int WindowWidth(WINDOW wnd)
These functions return the window's height and width.
-------------------------------------------------------------------
int ClientWidth(WINDOW wnd)
int ClientHeight(WINDOW wnd)
These functions return the height and width of the window's client
area.
-------------------------------------------------------------------
int GetTop(WINDOW wnd)
int GetBottom(WINDOW wnd)
int GetLeft(WINDOW wnd)
int GetRight(WINDOW wnd)
These functions return the screen coordinates of the four corners of
the window.
-------------------------------------------------------------------
int GetClientTop(WINDOW wnd)
int GetClientBottom(WINDOW wnd)
int GetClientLeft(WINDOW wnd)
int GetClientRight(WINDOW wnd)
These functions return the screen coordinates of the four corners of
the window's client area.
-------------------------------------------------------------------
WINDOW GetParent(WINDOW wnd)
Returns the parent of the window or NULLWND if the window has no
parent.
-------------------------------------------------------------------
WINDOW GetFirstChild(WINDOW pwnd)
Returns the first child of a parent window or NULLWND if the window
has no children.
-------------------------------------------------------------------
WINDOW GetNextChild(WINDOW pwnd, WINDOW cwnd)
Call this function repetitively after GetFirstChild. It returns the
next child window after the one specified in the second parameter. If
there are no more children, the function returns NULLWND.
-------------------------------------------------------------------
WINDOW GetLastChild(WINDOW pwnd)
Returns the last child of a p`rent window or NULLWND if the window
has no children.
-------------------------------------------------------------------
WINDOW GetPrevChild(WINDOW pwnd, WINDOW wnd)
Call this function repetitively after GetLastChild. It returns the
previous child window before the one specified in the second
parameter. If there are no more children, the function returns
NULLWND.
-------------------------------------------------------------------
int CharInView(WINDOW wnd, int x, int y)
Returns true if the x/y character position, relative to the window,
is in view (not clipped at the border of a parent window or the
screen.
-------------------------------------------------------------------
int TopBorderAdj(WINDOW wnd)
Returns the value to add to a y coordinate of the window's client
area to make it relative to the window top.
-------------------------------------------------------------------
int BorderAdj(WINDOW wnd)
Returns the value to add to an x coordinate relative to the window's
client area to make it relative to the window's left edge.
-------------------------------------------------------------------
char *GetTitle(WINDOW wnd)
Returns the address of a window's title, or NULL if the window has no
title.
-------------------------------------------------------------------
void AddTitle(WINDOW wnd, char *title)
Adds or changes the title to an existing window.
-------------------------------------------------------------------
CLASS GetClass(WINDOW wnd)
Returns the class of the window.
-------------------------------------------------------------------
int GetAttribute(WINDOW wnd)
Returns the attribute word of a window.
-------------------------------------------------------------------
void AddAttribute(WINDOW wnd, int attrib)
Adds one or more attributes to a window. OR the attribute values
together.
-------------------------------------------------------------------
void ClearAttribute(WINDOW wnd, int attrib)
Clears one or more attributes from a window. OR the attribute values
together.
-------------------------------------------------------------------
int TestAttribute(WINDOW wnd, int attrib)
Tests one or more attributes in a window. Returns true if any of them
are set. OR the attribute values together.
-------------------------------------------------------------------
int isVisible(WINDOW wnd)
Returns true if the window is visible.
-------------------------------------------------------------------
char *GetText(WINDOW wnd)
Returns the address of the text buffer for a TEXTBOX or derived
window class.
-------------------------------------------------------------------
char *TextLine(WINDOW wnd, int line)
Returns the address of a specified line of text (0, 1, ...) in a
TEXTBOX or derived class.
-------------------------------------------------------------------
WINDOW inWindow(int x, int y)
Returns the WINDOW handle of the window that x/y are in or NULL if
x/y is outside of any window.
-------------------------------------------------------------------
int isActive(MENU *mnu, int command)
Returns true if the command (commands.h) on the menu is active
(enabled).
-------------------------------------------------------------------
void ActivateCommand(MENU *mnu, int command)
void DeactivateCommand(MENU *mnu, int command)
Activate (enable) or deactivate (disable) a command (commands.h) on a
menu.
-------------------------------------------------------------------
int GetCommandToggle(MENU *mnu, int command)
void SetCommandToggle(MENU *mnu, int command)
void ClearCommandToggle(MENU *mnu, int command)
void InvertCommandToggle(MENU *mnu, int command)
Some menu commands are toggles rather than executors of processes.
Examples are the Insert and Word wrap commands on the Options menu.
These functions get, set, clear, and invert the toggle setting for a
specified command on a specified menu.
-------------------------------------------------------------------
int ItemSelected(WINDOW wnd, int line)
This function returns true if the specified item (0, 1, ...) on a
multiple-line selection listbox is selected.
-------------------------------------------------------------------
int DialogBox(
WINDOW wnd, /* parent window of the dialog box */
DBOX *db, /* address of dialog box definition array */
int Modal, /* trus if it is a modal dialog box */
int (*wndproc)(struct window *, MESSAGE, PARAM, PARAM)
/* the window processing function or NULL */
)
This function executes a dialog box. If it is a modal dialog box, the
function does not return until the user completes the dialog box. The
return value will be true if the user has selected OK and false if
the user has selected Cancel on the dialog box. If the dialog box is
modeless, the function returns immediately, and the user can select
other things from the screen while the dialog box is still active.
-------------------------------------------------------------------
int DlgOpenFile(char *filespec, char *filename)
This function operates the Open File dialog box. The filespec pointer
points to a default file path specification that the dialog box uses
to display files, for example, *.DOC. If the function returns true,
the space pointed to by the filename pointer will contain the path
and filename selected by the user to be read.
-------------------------------------------------------------------
int DlgSaveAs(char *filename)
This function operates the Save As dialog box. If the function returns
true, the space pointed to by the filename pointer will contain the
path and filename selected by the user where the file will be
written.
-------------------------------------------------------------------
void MessageBox(char *title, char *message)
void ErrorMessage(char *message)
int TestErrorMessage(char *message)
int YesNoBox(char *question)
WINDOW MomentaryMessage(char *message)
These functions display generic message boxes. The message text is
one null-terminated string with newlines (\n) to indicate where lines
are to be broken. The size of the boxes adjusts to the width of the
longest line and the number of lines of text. A message may have no
more lines of text than will fit into the largest window that the
screen can display. You must account for the window's border's and
the presence at the bottom of one or more command buttons.
The MessageBox function displays a message in a window with a title
provided by the caller. The window contains the message and an OK
command button.
The ErrorMessage function displays the message in an error box window
with an OK command button.
The TestErrorMessage function is an error message with OK and Cancel
command buttons. The function returns true if the user selects OK or
presses Enter and false if the user selects Cancel or presses Esc.
The YesNoBox function displays the message with Yes and No command
buttons. The function returns true if the user selects Yes or
presses Enter and false if the user selects No or presses Esc.
The MomentaryMessage function displays a message box and returns its
WINDOW handle. The caller must close the window. The purpose of this
function is to allow you to display a message while some time
consuming process is underway and then erase the message after the
process is done but without any action required from the user.
-------------------------------------------------------------------
int RadioButtonSetting(DBOX *db, enum commands cmd)
This function returns true if the specified command on the specified
dialog box is a pressed radio button.
-------------------------------------------------------------------
void EnableButton(DBOX *db, enum commands cmd)
This function enables a command button on a dialog box. command
buttons are initially enabled when the dialog box is first opened.
-------------------------------------------------------------------
void DisableButton(DBOX *db, enum commands cmd)
This function disables a command button on a dialog box. command
buttons are initially enabled when the dialog box is first opened.
-------------------------------------------------------------------
void PushRadioButton(DBOX *db, enum commands cmd)
This function presses the specified radio button command on the
specified dialog box.
-------------------------------------------------------------------
void PutItemText(WINDOW wnd, enum commands cmd, char *text)
This function appends a line of text to a TEXT, TEXTBOX, or EDITBOX
control window in a dialog box. The wnd parameter is the WINDOW
handle of the dialog box. The cmd parameter specifies the command
associated with the control item. The text parameter points to the
text to be added. The control window makes it own copy of the text,
so the caller's copy can go out of scope. If the control window is a
TEXTBOX or EDITBOX window, you must send a PAINT message to the
control window so that the new text will display.
You must call this function while the dialog box is active. That
means that if the dialog box is modal, you must call this function
from within a custom window processing function that you supply when
you call DialogBox.
-------------------------------------------------------------------
void GetItemText(WINDOW wnd, enum commands cmd, char *text, int length)
This function copies the text from a TEXT, TEXTBOX, or EDITBOX
control window in a dialog box. The wnd parameter is the WINDOW
handle of the dialog box. The cmd parameter specifies the command
associated with the control item. The text parameter points to the
caller's buffer where the text will be copied. The length parameter
specifies the maximum number of characters to copy.
You must call this function while the dialog box is active. That
means that if the dialog box is modal, you must call this function
from within a custom window processing function that you supply when
you call DialogBox.
-------------------------------------------------------------------
char *GetEditBoxText(DBOX *db, enum commands cmd)
This function returns a pointer to the text associated with an
editbox control in a dialog box. You can call it after the dialog box
has completed processing. The buffer is on the heap. Do not free it.
Instead, call SetEditBoxText with a NULL pointer.
If the text has not changed since it was initialized, this function
returns NULL.
-------------------------------------------------------------------
void SetEditBoxText(DBOX *db, enum commands cmd, char *text)
This function sets the text of a dialog box editbox. You can call
this function before the dialog box is open. The dialog box makes it
own copy on the heap, so your text can go out of scope.
-------------------------------------------------------------------
void SetCheckBox(DBOX *db, enum commands cmd)
void ClearCheckBox(DBOX *db, enum commands cmd)
int CheckBoxSetting(DBOX *db, enum commands cmd)
These functions set, clear, and test the setting of a specified check
box control item on a dialog box.
-------------------------------------------------------------------
void LoadHelpFile(char *expath);
This function loads the help file named by the DFLAT_APPLICATION
global constant with the .HLP file extension. The expath parameter
points to the DOS path where the file can be found.
Call this function at the beginning of an application program.
-------------------------------------------------------------------
void UnLoadHelpFile(void);
Call this function at the end of a D-Flat application to free the
memory used by a help file.
-------------------------------------------------------------------
void WriteTextLine(WINDOW wnd, RECT *rcc, int y, int reverse)
This function displays a text line from a TEXTBOX or derived window
class. The text has apready been added to the window with ADDTEXT,
etc. The y parameter specifies which line (0, 1, ...) relative to the
window's text buffer to display. If the specified line is not in
view, the function does nothing. If the reverse parameter is true,
the line displays in the reverse-video colors of the window. The rcc
RECT pointer is usually NULL for applications calls. It points to a
rectangle relative to the window outside of which displays will not
occur.
This function calls the writeline function, so an application can
embed CHANGECOLOR and RESETCOLOR commands in the text.
-------------------------------------------------------------------
void writeline(WINDOW wnd, char *line, int x, int y, int pad)
This function writes a line of text to a window. The x and y
coordinates point to the first character in the window's client area
where the line is to be written. The text must be null-terminated.
This function clips the line if it goes beyond the screen. If the
window does not have the NOCLIP attribute, the function clips the
line if it goes outside the borders of the window's parent. If the
pad parameter is true, writeline pads the window's line to its right
margin with spaces.
This function calls the wputs function, so an application can embed
CHANGECOLOR and RESETCOLOR commands in the text.
------------------------------------------------------------------- v
void wputs(WINDOW wnd, void *line, int x, int y)
This function writes a line of text to a window. The x and y
coordinates point to the first character in the window's client area
where the line is to be written. The text must be null-terminated.
The caller can embed color change commands in the text. If the
CHANGECOLOR code occurs, the next two characters are the foreground
and background color values. These colors continue on the line until
the end of the line or the RESETCOLOR code occurs.
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void PutWindowChar(WINDOW wnd, int x, int y, int c)
This function writes the character c to a window. The x and y
coordinates are relative to the window's client area.
The function performs clipping. If the character is beyond the
screen's dimensions it is not written. If the window does not have
the NOCLIP attribute, the character is not written if its coordinates
are beyond the margins of its parent window (if the window has a
parent).
-------------------------------------------------------------------
void wputch(WINDOW wnd, int c, int x, int y)
This function writes the character c to a window. The x and y
coordinates are relative to the window's client area.
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