/ 
TUI-Vision-2.000_003
/ TView

NAME

TView - base class for all visual components in Turbo Vision

HIERARCHY

TObject
  TView

SYNOPSIS

use TUI::Views;

my $view = TView->new(bounds => $bounds);
$view->draw();
$view->handleEvent($event);

DESCRIPTION

TView is the fundamental base class for all visible objects in Turbo Vision. Every visual component shown on the screen ultimately derives from TView.

The class provides the core infrastructure required for drawing, event handling, coordinate transformation, focus management, command processing, and interaction with the owning view hierarchy. Most applications do not use TView directly but instead instantiate one of its many descendants such as dialogs, windows, list viewers, or menu views.

TView defines a large number of methods, many of which are intended for internal use or for implementation by subclasses. Application code typically interacts with TView through state flags, command handling, drawing helpers, and event dispatch.

The behavior and appearance of a view are controlled primarily through its state, options, event mask, and geometry attributes.

Commonly Used Features

In day-to-day application code, the most relevant configuration fields are growMode, dragMode, helpCtx, state, options, and eventMask. They define resize behavior, input handling, help context, and event routing.

The methods most commonly touched outside framework internals are clearEvent, commandEnabled, dataSize, disableCommands, draw, drawView, enableCommands, getColor, getCommands, getHelpCtx, getPalette, getState, hideCursor, normalCursor, select, setCommands, setState, show, showCursor, valid, writeLine, and writeStr.

VARIABLES

The following global variables define default behavior and visual properties shared by all TView objects.

$shadowSize

Default size of the view shadow, specified as a TPoint.

$shadowAttr

Attribute value used when drawing view shadows.

$showMarkers

Controls whether focus and selection markers are displayed.

$specialChars

Array reference defining special navigation and marker characters.

$errorAttr

Attribute value used to render views in an error state.

$commandSetChanged

Indicates whether the active command set has been modified.

$curCommandSet

Holds the current default command set used for command enabling and dispatch.

ATTRIBUTES

The following attributes define the geometry, state, and ownership of a view. Unless otherwise noted, attributes are part of the public view state and may be read or modified by application code.

next

Internal link to the next view in the owner's Z-ordered view list. This attribute is managed internally.

size

Size of the view as a TPoint.

origin

Upper-left corner of the view relative to its owner.

cursor

Current cursor position within the view.

owner

Owning group of this view (TGroup). This reference is managed internally.

options

View option flags (Int), typically a combination of ofXXXX constants.

eventMask

Event mask controlling which event classes are accepted by the view.

state

Current state flags of the view, such as visibility, selection, and cursor mode (sfXXXX constants).

growMode

Grow mode flags controlling how the view resizes when its owner changes size (gfXXXX constants).

dragMode

Drag behavior flags controlling how the view responds to mouse dragging (dmXXXX constants).

helpCtx

Help context identifier associated with the view.

CONSTRUCTOR

new

my $view = TView->new(bounds => $bounds);

Creates and initializes a new view with the specified bounding rectangle. The view is created with default state, option, and event mask values.

bounds

Bounding rectangle of the view (TRect).

new_TView

my $view = new_TView($bounds);

Factory-style constructor using positional arguments.

This constructor is equivalent to calling new with the bounds parameter and is provided for compatibility with traditional Turbo Vision construction patterns.

DESTRUCTOR

DEMOLISH

$self->DEMOLISH($in_global_destruction);

Destroys the view and removes it from the screen and the view hierarchy. This method corresponds to the Turbo Vision destructor and is normally called automatically by the owning group.

METHODS

TView defines a comprehensive set of methods for drawing, event handling, state management, and interaction with the view hierarchy. Many of these methods are intended to be used by subclasses or internally by the framework.

new

my $view = TView->new(bounds => $bounds);

Initializes an instance of TView with the specified bounds.

bounds

The bounds of the view (TRect).

DEMOLISH

$self->DEMOLISH();

TopView

my $view = $self->TopView();

Returns the top view in the view hierarchy.

awaken

$self->awaken();

Prepares the view for activation.

blockCursor

$self->blockCursor();

Sets the cursor to block mode.

calcBounds

$self->calcBounds($bounds, $delta);

Calculates the bounds of the view based on the given delta.

changeBounds

$self->changeBounds($bounds);

Changes the bounds of the view.

clearEvent

$self->clearEvent($event);

Clears the specified event.

commandEnabled

my $bool = TView->commandEnabled($command);

Checks if the specified command is enabled.

containsMouse

my $bool = $self->containsMouse($event);

Checks if the mouse is within the view's bounds.

dataSize

my $size = $self->dataSize();

Returns the size of the view's data.

disableCommand

$self->disableCommand($command);

Disables the specified command.

disableCommands

$self->disableCommands($commands);

Disables the specified commands.

dragView

$self->dragView($event, $mode, $limits, $minSize, $maxSize);

Handles the dragging of the view.

draw

$self->draw();

Draws the view on the screen.

drawCursor

$self->drawCursor();

Draws the cursor in the view.

drawHide

$self->drawHide($lastView | undef);

Hides the view by drawing over it.

drawShow

$self->drawShow($lastView | undef);

Shows the view by drawing it.

drawUnderRect

$self->drawUnderRect($r, $lastView | undef);

Draws the view under the specified rectangle.

drawUnderView

$self->drawUnderView($doShadow, $lastView | undef);

Draws the view under another view.

drawView

$self->drawView();

Draws the view.

enableCommand

$self->enableCommand($command);

Enables the specified command.

enableCommands

$self->enableCommands($commands);

Enables the specified commands.

endModal

$self->endModal($command);

Ends the modal state of the view.

eventAvail

my $bool = $self->eventAvail();

Checks if an event is available.

execute

my $cmd = $self->execute();

Executes the view.

exposed

my $bool = $self->exposed();

Checks if the view is exposed.

focus

my $bool = $self->focus();

Sets the focus to the view.

getBounds

my $rect = $self->getBounds();

Returns the bounds of the view.

getClipRect

my $rect = $self->getClipRect();

Returns the clipping rectangle of the view.

getColor

my $int = $self->getColor($color);

Returns the color of the view.

getCommands

$self->getCommands($commands);

Gets the commands of the view.

getData

$self->getData(\@rec);

Returns the data of the view.

getEvent

$self->getEvent($event);

Gets the specified event.

getExtent

my $rect = $self->getExtent();

Returns the extent of the view.

getHelpCtx

my $int = $self->getHelpCtx();

Returns the help context of the view.

getPalette

my $palette = $self->getPalette();

Returns the view's color palette.

getState

my $bool = $self->getState($aState);

Returns the state of the view.

growTo

$self->growTo($x, $y);

Grows the view to the specified size.

handleEvent

$self->handleEvent($event);

Handles an event sent to the view.

hide

$self->hide();

Hides the view.

hideCursor

$self->hideCursor();

Hides the cursor in the view.

keyEvent

$self->keyEvent($event);

Handles a key event.

locate

$self->locate($bounds);

Positions the view within the specified bounds.

makeFirst

my $void = $self->makeFirst();

Moves the view to the front of the view hierarchy.

makeGlobal

my $point = $self->makeGlobal($source);

Converts a local point to a global point.

makeLocal

my $point = $self->makeLocal($source);

Converts a global point to a local point.

mapColor

my $int = $self->mapColor($color);

Maps a color to the view's palette.

mouseEvent

my $bool = $self->mouseEvent($event, $mask);

Handles a mouse event.

mouseInView

my $bool = $self->mouseInView($mouse);

Checks if the mouse is within the view.

moveTo

$self->moveTo($x, $y);

Moves the view to the specified position.

nextView

my $view | undef = $self->nextView();

Returns the next view in the view hierarchy.

normalCursor

$self->normalCursor();

Sets the cursor to normal mode.

prev

my $view | undef = $self->prev();

Returns the previous view in the view hierarchy.

prevView

my $view | undef = $self->prevView();

Returns the previous view in the view hierarchy.

putEvent

$self->putEvent($event);

Puts an event in the event queue.

putInFrontOf

$self->putInFrontOf($target | undef);

Puts the view in front of the specified target view.

resetCursor

$self->resetCursor();

Resets the cursor in the view.

select

$self->select();

Selects the view.

setBounds

$self->setBounds($bounds);

Sets the bounds of the view to the specified values.

setCmdState

$self->setCmdState($commands, $enable);

Sets the command state of the view.

setCommands

$self->setCommands($commands);

Sets the commands of the view.

setCursor

$self->setCursor($x, $y);

Sets the position of the cursor in the view to the specified values.

setData

$self->setData($rec);

Sets the data of the view to the specified values.

setState

$self->setState($aState, $enable);

Sets the state of the view to the specified value.

show

$self->show();

Shows the view.

showCursor

$self->showCursor();

Displays the cursor in the view.

shutDown

$self->shutDown();

Shuts down the view.

sizeLimits

$self->sizeLimits($min, $max);

Determines the minimum and maximum sizes of the view.

valid

my $bool = $self->valid($command);

Checks if the view is valid for the specified command.

writeBuf

$self->writeBuf($x, $y, $w, $h, $b);

Writes a buffer to the view.

writeChar

$self->writeChar($x, $y, $c, $color, $count);

Writes a character to the view.

writeLine

$self->writeLine($x, $y, $w, $h, $b);

Writes a line to the view.

writeStr

$self->writeStr($x, $y, $str, $color);

Writes a string to the view.

AUTHORS

Borland International (original Turbo Vision design)
J. Schneider <brickpool@cpan.org> (Perl implementation and maintenance)

COPYRIGHT AND LICENSE

Copyright (c) 1990-1994, 1997 by Borland International

Copyright (c) 2021-2026 the "AUTHORS" as listed above.

This software is licensed under the MIT license (see the LICENSE file, which is part of the distribution). This documentation is provided under the same terms as the Turbo Vision library itself.