PySide6.QtGui.QStaticText¶
- class QStaticText¶
The
QStaticText
class enables optimized drawing of text when the text and its layout is updated rarely. More…Synopsis¶
Methods¶
def
__init__()
def
__ne__()
def
__eq__()
def
prepare()
def
setText()
def
setTextFormat()
def
setTextOption()
def
setTextWidth()
def
size()
def
swap()
def
text()
def
textFormat()
def
textOption()
def
textWidth()
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description¶
QStaticText
provides a way to cache layout data for a block of text so that it can be drawn more efficiently than by usingdrawText()
in which the layout information is recalculated with every call.The class primarily provides an optimization for cases where the text, its font and the transformations on the painter are static over several paint events. If the text or its layout is changed for every iteration,
drawText()
is the more efficient alternative, since the static text’s layout would have to be recalculated to take the new state into consideration.Translating the painter will not cause the layout of the text to be recalculated, but will cause a very small performance impact on drawStaticText(). Altering any other parts of the painter’s transformation or the painter’s font will cause the layout of the static text to be recalculated. This should be avoided as often as possible to maximize the performance benefit of using
QStaticText
.In addition, only affine transformations are supported by drawStaticText(). Calling drawStaticText() on a projected painter will perform slightly worse than using the regular drawText() call, so this should be avoided.
class MyWidget: public QWidget { public: MyWidget(QWidget *parent = nullptr) : QWidget(parent), m_staticText("This is static text") protected: void paintEvent(QPaintEvent *) { QPainter painter(this); painter.drawStaticText(0, 0, m_staticText); } private: QStaticText m_staticText; };
The
QStaticText
class can be used to mimic the behavior ofdrawText()
to a specific point with no boundaries, and also whendrawText()
is called with a bounding rectangle.If a bounding rectangle is not required, create a
QStaticText
object without setting a preferred text width. The text will then occupy a single line.If you set a text width on the
QStaticText
object, this will bound the text. The text will be formatted so that no line exceeds the given width. The text width set forQStaticText
will not automatically be used for clipping. To achieve clipping in addition to line breaks, usesetClipRect()
. The position of the text is decided by the argument passed todrawStaticText()
and can change from call to call with a minimal impact on performance.For extra convenience, it is possible to apply formatting to the text using the HTML subset supported by
QTextDocument
.QStaticText
will attempt to guess the format of the input text usingmightBeRichText()
, and interpret it as rich text if this function returnstrue
. To forceQStaticText
to display its contents as either plain text or rich text, use the functionsetTextFormat()
and pass in, respectively, Qt::PlainText and Qt::RichText.QStaticText
can only represent text, so only HTML tags which alter the layout or appearance of the text will be respected. Adding an image to the input HTML, for instance, will cause the image to be included as part of the layout, affecting the positions of the text glyphs, but it will not be displayed. The result will be an empty area the size of the image in the output. Similarly, using tables will cause the text to be laid out in table format, but the borders will not be drawn.If it’s the first time the static text is drawn, or if the static text, or the painter’s font has been altered since the last time it was drawn, the text’s layout has to be recalculated. On some paint engines, changing the matrix of the painter will also cause the layout to be recalculated. In particular, this will happen for any engine except for the OpenGL2 paint engine. Recalculating the layout will impose an overhead on the
drawStaticText()
call where it occurs. To avoid this overhead in the paint event, you can callprepare()
ahead of time to ensure that the layout is calculated.- class PerformanceHint¶
This enum the different performance hints that can be set on the
QStaticText
. These hints can be used to indicate that theQStaticText
should use additional caches, if possible, to improve performance at the expense of memory. In particular, setting the performance hint AggressiveCaching on theQStaticText
will improve performance when using the OpenGL graphics system or when drawing to a QOpenGLWidget.Constant
Description
QStaticText.ModerateCaching
Do basic caching for high performance at a low memory cost.
QStaticText.AggressiveCaching
Use additional caching when available. This may improve performance at a higher memory cost.
- __init__()¶
Constructs an empty
QStaticText
- __init__(other)
- Parameters:
other –
QStaticText
Constructs a
QStaticText
object which is a copy ofother
.- __init__(text)
- Parameters:
text – str
Constructs a
QStaticText
object with the giventext
.- __ne__(other)¶
- Parameters:
other –
QStaticText
- Return type:
bool
Compares
other
to thisQStaticText
. Returnstrue
if the texts, fonts or maximum sizes are different.- __eq__(other)¶
- Parameters:
other –
QStaticText
- Return type:
bool
Compares
other
to thisQStaticText
. Returnstrue
if the texts, fonts and text widths are equal.- performanceHint()¶
- Return type:
Returns which performance hint is set for the
QStaticText
.See also
- prepare([matrix=QTransform()[, font=QFont()]])¶
- Parameters:
matrix –
QTransform
font –
QFont
Prepares the
QStaticText
object for being painted with the givenmatrix
and the givenfont
to avoid overhead when the actual drawStaticText() call is made.When drawStaticText() is called, the layout of the
QStaticText
will be recalculated if any part of theQStaticText
object has changed since the last time it was drawn. It will also be recalculated if the painter’s font is not the same as when theQStaticText
was last drawn, or, on any other paint engine than the OpenGL2 engine, if the painter’s matrix has been altered since the static text was last drawn.To avoid the overhead of creating the layout the first time you draw the
QStaticText
after making changes, you can use the prepare() function and pass in thematrix
andfont
you expect to use when drawing the text.See also
- setPerformanceHint(performanceHint)¶
- Parameters:
performanceHint –
PerformanceHint
Sets the performance hint of the
QStaticText
according to theperformanceHint
provided. TheperformanceHint
is used to customize how much caching is done internally to improve performance.The default is
ModerateCaching
.Note
This function will cause the layout of the text to require recalculation.
See also
- setText(text)¶
- Parameters:
text – str
Sets the text of the
QStaticText
totext
.- setTextFormat(textFormat)¶
- Parameters:
textFormat –
TextFormat
Sets the text format of the
QStaticText
totextFormat
. IftextFormat
is set to Qt::AutoText (the default), the format of the text will try to be determined using the functionmightBeRichText()
. If the text format is Qt::PlainText, then the text will be displayed as is, whereas it will be interpreted as HTML if the format is Qt::RichText. HTML tags that alter the font of the text, its color, or its layout are supported byQStaticText
.Note
This function will cause the layout of the text to require recalculation.
See also
- setTextOption(textOption)¶
- Parameters:
textOption –
QTextOption
Sets the text option structure that controls the layout process to the given
textOption
.See also
- setTextWidth(textWidth)¶
- Parameters:
textWidth – float
Sets the preferred width for this
QStaticText
. If the text is wider than the specified width, it will be broken into multiple lines and grow vertically. If the text cannot be split into multiple lines, it will be larger than the specifiedtextWidth
.Setting the preferred text width to a negative number will cause the text to be unbounded.
Use
size()
to get the actual size of the text.Note
This function will cause the layout of the text to require recalculation.
See also
Returns the size of the bounding rect for this
QStaticText
.See also
- swap(other)¶
- Parameters:
other –
QStaticText
Swaps this static text instance with
other
. This function is very fast and never fails.- text()¶
- Return type:
str
Returns the text of the
QStaticText
.See also
- textFormat()¶
- Return type:
Returns the text format of the
QStaticText
.See also
- textOption()¶
- Return type:
Returns the current text option used to control the layout process.
See also
- textWidth()¶
- Return type:
float
Returns the preferred width for this
QStaticText
.See also