SYNOPSIS

Perl

use HaikuR1::Application;
use HaikuR1::Window;
use HaikuR1::View

Python

from HaikuR1.ApplicationKit import Application
from HaikuR1.InterfaceKit import Window
from HaikuR1.InterfaceKit import View

DESCRIPTION

This document contains the View functions that have to do with drawing - both the functions that actually do the drawing and the functions that relate to the drawing state.

These functions are mainly useful for:

Creating custom subclasses
Recording Pictures
Drawing to Bitmaps

However, the font and color methods may also be of more general use if you want to change only those aspects of a View, without otherwise customizing its behavior.

For more information on these methods, see https://www.haiku-os.org/legacy-docs/bebook/BView.html#BView_Graphics and https://www.haiku-os.org/legacy-docs/bebook/BView.html#BView_Drawing.

METHODS

Blending Mode

GetBlendingMode

SetBlendingMode

Gets or sets the blending mode.

Perl

$view->GetBlendingMode();
$view->SetBlendingMode($srcAlpha, $alphaFunc);

Python

view.GetBlendingMode()
view.SetBlendingMode(srcAlpha, alphaFunc)

srcAlpha

An integer, one of the source alpha constants.
alphaFunc

An integer, one of the alpha function constants.

Clipping

GetClippingRegion

ConstrainClippingRegion

ClipToRect

ClipToInverseRect

ClipToPicture

ClipToInversePicture

ClipToShape

ClipToInverseShape

GetClippingRegion returns the current clipping Region (the area where the View is allowed to draw).

ConstrainClippingRegion combines the given Region with the View's internal clipping region; the Viewmay only draw on the intersection of the two regions.

ClipToPicture combines the View's clipping Region with the given Picture; the View will only be able to draw on pixels that are contained within the View's clipping region and are drawn by the Picture.

ClipToInversePicture is like ClipToPicture, but the View will only be able to draw on picutres that are not drawn by the Picture.

Perl

$view->GetClippingRegion();
$view->ConstrainClippingRegion($region);
$view->ClipToRect($rect);
$view->ClipToInverseRect($rect);
$view->ClipToPicture($picture, $where, $sync);
$view->ClipToInversePicture($picture, $where, $sync);
$view->ClipToShape($shape);
$view->ClipToInverseShape($shape);

Python

view.GetClippingRegion()
view.ConstrainClippingRegion(region)
view.ClipToRect(rect)
view.ClipToInverseRect(rect)
view.ClipToPicture(picture, where, sync)
view.ClipToInversePicture(picture, where, sync)
view.ClipToShape(shape)
view.ClipToInverseShape(shape)

region

The Region to combine with the clipping region.
rect

The Rect to clip to.
picture

The Picture to clip to.
where

The origin Point, in the View's coordinate space.
sync

A boolean, if true (the default), then the function will not return until the it is complete; otherwise the it will return immediately and the function will complete asynchronously.
shape

The Shape to clip to.

Colors

ViewColor

SetViewColor

HighColor

SetHighColor

LowColor

SetLowColor

ViewUIColor

SetViewUIColor

HighUIColor

SetHighUIColor

LowUIColor

SetLowUIColor

HasDefaultColors

HasSystemColors

AdoptParentColors

AdoptSystemColors

AdoptViewColors

The Color and UIColor methods get or set the given color for the View. The "view color" is the background color for the view. The "high" and "low" colors refer to the pattern argument taken by many drawing operations.

The Set*X*Color methods also serve as hooks (unlike the Set*X*UIColor.

The Has methods test whether the View has the indicated color scheme.

The Adopt methods set the View's color scheme to the given scheme.

Perl

$view->ViewColor();
$view->SetViewColor($color);
$view->HighColor();
$view->SetHighColor($color);
$view->LowColor();
$view->SetLowColor($color);
$view->ViewUIColor();
$view->SetViewUIColor($ui_color);
$view->HighUIColor();
$view->SetHighUIColor($ui_color);
$view->LowUIColor();
$view->SetLowUIColor($ui_color);
$view->HasDefaultColors();
$view->HasSystemColors();
$view->AdoptParentColors();
$view->AdoptSystemColors();
$view->AdoptViewColors($view);

Python

view.ViewColor()
view.SetViewColor(color)
view.HighColor()
view.SetHighColor(color)
view.LowColor()
view.SetLowColor(color)
view.ViewUIColor()
view.SetViewUIColor(ui_color)
view.HighUIColor()
view.SetHighUIColor(ui_color)
view.LowUIColor()
view.SetLowUIColor(ui_color)
view.HasDefaultColors()
view.HasSystemColors()
view.AdoptParentColors()
view.AdoptSystemColors()
view.AdoptViewColors(view)

color

An rgb_color.
ui_color

An integer UI color constant.
view

A View to adopt colors from.

DrawBitmap

DrawBitmapAsync

Draws a Bitmap onto the View.

DrawBitmap will not return until the bitmap has been drawn; DrawBitmapAsync will return immediately and the bitmap will be drawn asynchronously.

Perl

$view->DrawBitmap($bitmap);
$view->DrawBitmap(
    bitmap     => $bitmap,
    sourceRect => $bitmapRect,
    destRect   => $viewRect,
    options    => $options,
);
$view->DrawBitmap(
    bitmap     => $bitmap,
    where      => $where,
);
$view->DrawBitmapAsync($bitmap);
$view->DrawBitmapAsync(
    bitmap     => $bitmap,
    sourceRect => $bitmapRect,
    destRect   => $viewRect,
    options    => $options,
);
$view->DrawBitmapAsync(
    bitmap     => $bitmap,
    where      => $where,
);

Python

view.DrawBitmap(bitmap)
view.DrawBitmap(
    bitmap     = bitmap,
    sourceRect = bitmapRect,
    destRect   = viewRect,
    options    = options,
)
view.DrawBitmap(
    bitmap     = bitmap,
    where      = where,
)
view.DrawBitmapAsync(bitmap)
view.DrawBitmapAsync(
    bitmap     = bitmap,
    sourceRect = bitmapRect,
    destRect   = viewRect,
    options    = options,
)
view.DrawBitmapAsync(
    bitmap     = bitmap,
    where      = where,
)

bitmap

The Bitmap to draw.
sourceRect

A Rect representing the portion of the bitmap to copy; if omitted, will draw the entire bitmap.
destRect

A Rect representing the area of the View to draw into; if omitted, the bitmap will be drawn unscaled.
where

A Point representing the location to draw an unscaled bitmap into; if both destRect and where are amitted, will draw to the current pen location.
options

An integer, additional options, one or more of the bitmap drawing options constants.

DrawingMode

SetDrawingMode

Gets or sets the drawing mode.

Perl

$view->DrawingMode();
$view->SetDrawingMode($mode);

Python

view.DrawingMode()
view.SetDrawingMode(mode)

mode

An integer, one of the drawing mode constants.

Font

GetFont

SetFont

SetFontSize

These functions do what you expect.

Perl

$view->GetFont();
$view->SetFont($font, $mask);
$view->SetFontSize($size);

Python

view.GetFont()
view.SetFont(font, mask)
view.SetFontSize(size)

size

A floating point number, the new size.
font

A Font object.
mask

An integer, one or more ofthe font properties constants; defaults to B_FONT_ALL.

InvertRect

Inverts the colors within a rectangle.

Perl

$view->InvertRect($rect);

Python

view.InvertRect(rect)

rect

A Rect, the rectangle

Layers

BeginLayer

EndLayer

Allows a "layer" of drawing operations to be drawn with a given opacity.

Perl

$view->BeginLayer($opacity);
$view->EndLayer();

Python

view.BeginLayer(opacity)
view.EndLayer()

opacity

An integer, the opacity level.

Line settings

LineCapMode

LineJoinMode

LineMiterLimit

SetLineMode

Gets or sets the line cap and line join modes and the line miter limit.

Perl

$view->LineCapMode();
$view->LineJoinMode();
$view->LineMiterLimit();
$view->SetLineMode($lineCap, $lineJoin, $miterLimit);

Python

view.LineCapMode()
view.LineJoinMode()
view.LineMiterLimit()
view.SetLineMode(lineCap, lineJoin, miterLimit)

lineCap

One of the line cap mode constants.
lineJoin

One of the line join mode constants.
miterLimit

A floating point number; defaults to B_DEFAULT_MITER_LIMIT.

Origin

SetOrigin

Gets or sets the origin of the View's coordinate space.

Perl

$view->Origin();
$view->SetOrigin($point);

Python

view.Origin()
view.SetOrigin(point)

point

A Point, the origin.

PenLocation

MovePenTo

MovePenBy

Gets or sets the pen location.

Many of the drawing operations will change the pen location; this method moves it without drawing.

Perl

$view->PenLocation();
$view->MovePenTo($point);
$view->MovePenTo($x, $y);
$view->MovePenBy($x, $y);

Python

view.PenLocation()
view.MovePenTo(point)
view.MovePenTo(x, y)
view.MovePenBy(x, y)

point

A Point, the new pen location.
x, y

Floating point numbers, the new coordinates or the offsets to the new coordinates.

PenSize

SetPenSize

Gets or sets the pen size.

Perl

$view->PenSize();
$view->SetPenSize($size);

Python

view.PenSize()
view.SetPenSize(size)

A floating point number, the new size.

Recording and Playback

BeginPicture

AppendToPicture

SetDiskMode

EndPicture

DrawPicture

The first three operations begin a recording session; drawing operations will be saved instead of being drawn to the View.

BeginPicture will clear the given Picture; AppendToPicture will not.

SetDiskMode stores the drawing operations to a file instead of to a Picture object. (However, in the current version of Haiku, this method does nothing.)

EndPicture stops the recording session and returns a copy of the Picture.

DrawPicture plays back a recorded series of drwaing operations. Note that even though SetDiskMode is not yet implemented, the file version of DrawPicture is.

The Async version of DrawPicture retruns immediately, without waiting for the picture to be drawn.

Perl

$view->BeginPicture($picture);
$view->SetDiskMode($filename, $offset);
$view->AppendToPicture($picture);
$view->EndPicture();
$view->DrawPicture($picture, $where);
$view->DrawPicture($filename, $offset, $where);
$view->DrawPictureAsync($picture, $where);
$view->DrawPictureAsync($filename, $offset, $where);

Python

view.BeginPicture(picture)
view.SetDiskMode(filename, offset)
view.AppendToPicture(picture)
view.EndPicture()
view.DrawPicture(picture, where)
view.DrawPicture(filename, offset, where)
view.DrawPictureAsync(picture, where)
view.DrawPictureAsync(filename, offset, where)

picture

A Picture to record to or play back.
filename

A string, the filename to write to or read from.
offset

An integer, the offset into the file.
where

The Point where the picture should start; defaults to current pen location.

Scale

SetScale

Gets or sets the scale for drawing operations.

Perl

$view->Scale();
$view->SetScale($scale);

Python

view.Scale()
view.SetScale(scale)

scale

A floating point number, the scaling constant.

Shapes

StrokePolygon

FillPolygon

StrokeTriangle

FillTriangle

StrokeRect

FillRect

FillRegion

StrokeRoundRect

FillRoundRect

StrokeEllipse

FillEllipse

StrokeArc

FillArc

StrokeBezier

FillBezier

StrokeShape

FillShape

Strokes (draws the outline) or fills (draws and colors in) the given shape

Perl

# polygon
$view->StrokePolygon($polygon, $closed, $pattern);
$view->FillPolygon($polygon, $pattern);
$view->FillPolygon($polygon, $gradient);

# triangle
$view->StrokeTriangle($points, $pattern);
$view->FillTriangle($points, $pattern);
$view->FillTriangle($points, $gradient);

# rect
$view->StrokeRect($rect, $pattern);
$view->FillRect($rect, $pattern);
$view->FillRect($rect, $gradient);

# region
$view->FillRegion($region, $pattern);
$view->FillRegion($region, $gradient);

# round rect
$view->StrokeRoundRect($rect, $xRadius, $yRadius, $pattern);
$view->FillRoundRect($rect, $xRadius, $yRadius, $pattern);
$view->FillRoundRect($rect, $xRadius, $yRadius, $gradient);

# ellipse (from center and radii)
$view->StrokeEllipse($center, $xRadius, $yRadius, $pattern);
$view->FillEllipse($center, $xRadius, $yRadius, $pattern);
$view->FillEllipse($center, $xRadius, $yRadius, $gradient);

# ellipse (inscribed into rect)
$view->StrokeEllipseFromRect($rect, $pattern);
$view->FillEllipse($rect, $pattern);
$view->FillEllipse($rect, $gradient);

# ellipse arc (from center and radii)
$view->StrokeArc($center, $xRadius, $yRadius, $startAngle, $arcAngle, $pattern);
$view->FllArc($center, $xRadius, $yRadius, $startAngle, $arcAngle, $pattern);
$view->FllArc($center, $xRadius, $yRadius, $startAngle, $arcAngle, $gradient);

# ellipse arc (inscribed into rect)
$view->StrokeArc($rect, $startAngle, $arcAngle, $pattern);
$view->FllArc($rect, $startAngle, $arcAngle, $pattern);
$view->FllArc($rect, $startAngle, $arcAngle, $gradient);

# bezier curve
$view->StrokeBezier($controlPoints, $pattern);
$view->FillBezier($controlPoints, $pattern);
$view->FillBezier($controlPoints, $gradient);

# Shape object
$view->StrokeShape($shape, $pattern);
$view->FillShape($shape, $pattern);
$view->FillShape($shape, $gradient);

Python

# polygon
view.StrokePolygon(polygon, closed, pattern)
view.FillPolygon(polygon, pattern)
view.FillPolygon(polygon, gradient)

# triangle
view.StrokeTriangle(points, pattern)
view.FillTriangle(points, pattern)
view.FillTriangle(points, gradient)

# rect
view.StrokeRect(rect, pattern)
view.FillRect(rect, pattern)
view.FillRect(rect, gradient)

# region
view.FillRegion(region, pattern)
view.FillRegion(region, gradient)

# round rect
view.StrokeRoundRect(rect, xRadius, yRadius, pattern)
view.FillRoundRect(rect, xRadius, yRadius, pattern)
view.FillRoundRect(rect, xRadius, yRadius, gradient)

# ellipse (from center and radii)
view.StrokeEllipse(center, xRadius, yRadius, pattern)
view.FillEllipse(center, xRadius, yRadius, pattern)
view.FillEllipse(center, xRadius, yRadius, gradient)

# ellipse (inscribed into rect)
view.StrokeEllipseFromRect(rect, pattern)
view.FillEllipse(rect, pattern)
view.FillEllipse(rect, gradient)

# ellipse arc (from center and radii)
view.StrokeArc(center, xRadius, yRadius, startAngle, arcAngle, pattern)
view.FllArc(center, xRadius, yRadius, startAngle, arcAngle, pattern)
view.FllArc(center, xRadius, yRadius, startAngle, arcAngle, gradient)

# ellipse arc (inscribed into rect)
view.StrokeArc(rect, startAngle, arcAngle, pattern)
view.FllArc(rect, startAngle, arcAngle, pattern)
view.FllArc(rect, startAngle, arcAngle, gradient)

# bezier curve
view.StrokeBezier(controlPoints, pattern)
view.FillBezier(controlPoints, pattern)
view.FillBezier(controlPoints, gradient)

# Shape object
view.StrokeShape(shape, pattern)
view.FillShape(shape, pattern)
view.FillShape(shape, gradient)

polygon

Either a Polygon or a native list of Points, the polygon to draw.
closed

A boolean; if true (the default), a line will be drawn from the last point to the first, closing the polygon.
points

A native list of Points, the shape to draw.
rect

A Rect, the rectangle to draw or to inscribe the ellipse into.
center

A Point, the center
xRadius, yRadius

Floating point numbers, the x and y radii of the ellipse to draw, or in the case of the RoundRect methods, the ellipse to use for the corners.
startAngle, arcAngle

Floating point numbers, the span in degrees along which the arc will travel (i.e., start angle plus arc angle equals end angle)
controlPoints

A native list of four Points that define a Bezier curve.
shape

A Shape object.
pattern

A pattern; defaults to B_SOLID_HIGH (solid high color).
gradient

A Gradient to use (instead of a pattern).

Strings

DrawChar

DrawString

These methods do what you expect.

Perl

$view->DrawChar($char, $location);
$view->DrawString($string, $location);
$view->DrawString($string, $delta);
$view->DrawString($string, $location, $delta);
$view->DrawString($string, $locations);

Python

view.DrawChar(char, location)
view.DrawString(string, location)
view.DrawString(string, delta)
view.DrawString(string, location, delta)
view.DrawString(string, locations)

char

The character to draw; it must be a single-byte character (no UTF-8).
string

The string to draw.
location

Optional; the Point to draw the character or string at.
delta

An optional escapement_delta
locations

Optional; a native list of Points to draw the string at.

StrokeLine

BeginLineArray

AddLine

EndLineArray

StrokeLine draws a single line.

The other methods are a more efficient way of drawing multiple lines. The lines are drawn at all once by EndLineArray.

Perl

$view->StrokeLine($point1, $point2, $pattern);
$view->StrokeLine($point2, $pattern);
$view->BeginLineArray($count);
$view->AddLine($point1, $point2, $color);
$view->EndLineArray();

Python

view.StrokeLine(point1, point2, pattern)
view.StrokeLine(point2, pattern)
view.BeginLineArray(count)
view.AddLine(point1, point2, color)
view.EndLineArray()

point1

The start Point; can be omitted in StrokeLine, in which case the line will start from the current pen location.
point2

The end Point.
pattern

A pattern; defaults to B_SOLID_HIGH (solid high color).
count

An integer, the maximum number of lines that will be in this array. For memory purposes, it's good to keep this as close as possible to the actual number of lines you will draw; i.e., if you know in advance how many lines it will be, use that number; if there's wiggle room, don't give yourself a huge buffer just in case. The BeBook says that setting a value higher than 256 can affect memory performance.
color

An rgb_color, the line color.

Transformations

Transform

SetTransform

TranslateBy

ScaleBy

RotateBy

Sets the transform.

Perl

$view->Transform();
$view->SetTransform($transform);
$view->TranslateBy($x, $y);
$view->ScaleBy($x, $y);
$view->RotateBy($angleRadians);

Python

view.Transform()
view.SetTransform(transform)
view.TranslateBy(x, y)
view.ScaleBy(x, y)
view.RotateBy(angleRadians)

transform

An AffineTransform object.

View state

PushState

PopState

PushState pushes the current state onto the state stack, creating a new stack context. PopState pops the most recent state from the state stack, replacing the current stack context.

Perl

$view->PushState();
$view->PopState();

Python

view.PushState()
view.PopState()

HOOKS

Draw

Draws the View.

Perl

$view->Draw($rect);

Python

view.Draw(rect)

rect

A Rect, the invalid rectangle.

DrawAfterChildren

Called after all child Views have finished drawing.

Perl

$view->DrawAfterChildren($rect);

Python

view.DrawAfterChildren(rect)

rect

A Rect, the invalid rectangle.

CONSTANTS

Font properties

Perl

use HaikuR1::View qw(:font_mask)

Python

Python does not support export tags.

B_FONT_FAMILY_AND_STYLE
B_FONT_SIZE
B_FONT_SHEAR
B_FONT_ROTATION
B_FONT_SPACING
B_FONT_ENCODING
B_FONT_FACE
B_FONT_FLAGS
B_FONT_FALSE_BOLD_WIDTH
B_FONT_ALL