Module fpdf.graphics_state

Mixin class for managing a stack of graphics state variables.

The contents of this module are internal to fpdf2, and not part of the public API. They may change at any time without prior warning or any deprecation period, in non-backward-compatible ways.

Classes

class GraphicsStateMixin (*args, **kwargs)

Expand source code Browse git

class GraphicsStateMixin:
    """Mixin class for managing a stack of graphics state variables.

    To the subclassing library and its users, the variables look like
    normal instance attributes. But by the magic of properties, we can
    push and pop levels as needed, and users will always see and modify
    just the current version.

    This class is mixed in by fpdf.FPDF(), and is not meant to be used
    directly by user code.
    """

    DEFAULT_DRAW_COLOR = DeviceGray(0)
    DEFAULT_FILL_COLOR = DeviceGray(0)
    DEFAULT_TEXT_COLOR = DeviceGray(0)

    def __init__(self, *args, **kwargs):
        self.__statestack = [
            dict(
                draw_color=self.DEFAULT_DRAW_COLOR,
                fill_color=self.DEFAULT_FILL_COLOR,
                text_color=self.DEFAULT_TEXT_COLOR,
                underline=False,
                font_style="",
                font_stretching=100,
                char_spacing=0,
                font_family="",
                font_size_pt=0,
                current_font={},
                dash_pattern=dict(dash=0, gap=0, phase=0),
                line_width=0,
                text_mode=TextMode.FILL,
                char_vpos=CharVPos.LINE,
                sub_scale=0.7,
                sup_scale=0.7,
                nom_scale=0.75,
                denom_scale=0.75,
                sub_lift=-0.15,
                sup_lift=0.4,
                nom_lift=0.2,
                denom_lift=0.0,
                text_shaping=None,
            )
        ]
        super().__init__(*args, **kwargs)

    def _push_local_stack(self, new=None):
        if new:
            self.__statestack.append(new)
        else:
            self.__statestack.append(self._get_current_graphics_state())

    def _pop_local_stack(self):
        return self.__statestack.pop()

    def _get_current_graphics_state(self):
        # "current_font" must be shallow copied
        # "text_shaping" must be deep copied (different fragments may have different languages/direction)
        # Doing a whole copy and then creating a copy of text_shaping to achieve this result
        gs = copy(self.__statestack[-1])
        gs["text_shaping"] = copy(gs["text_shaping"])
        return gs

    def _is_current_graphics_state_nested(self):
        return len(self.__statestack) > 1

    @property
    def draw_color(self):
        return self.__statestack[-1]["draw_color"]

    @draw_color.setter
    def draw_color(self, v):
        self.__statestack[-1]["draw_color"] = v

    @property
    def fill_color(self):
        return self.__statestack[-1]["fill_color"]

    @fill_color.setter
    def fill_color(self, v):
        self.__statestack[-1]["fill_color"] = v

    @property
    def text_color(self):
        return self.__statestack[-1]["text_color"]

    @text_color.setter
    def text_color(self, v):
        self.__statestack[-1]["text_color"] = v

    @property
    def underline(self):
        return self.__statestack[-1]["underline"]

    @underline.setter
    def underline(self, v):
        self.__statestack[-1]["underline"] = v

    @property
    def font_style(self):
        return self.__statestack[-1]["font_style"]

    @font_style.setter
    def font_style(self, v):
        self.__statestack[-1]["font_style"] = v

    @property
    def font_stretching(self):
        return self.__statestack[-1]["font_stretching"]

    @font_stretching.setter
    def font_stretching(self, v):
        self.__statestack[-1]["font_stretching"] = v

    @property
    def char_spacing(self):
        return self.__statestack[-1]["char_spacing"]

    @char_spacing.setter
    def char_spacing(self, v):
        self.__statestack[-1]["char_spacing"] = v

    @property
    def font_family(self):
        return self.__statestack[-1]["font_family"]

    @font_family.setter
    def font_family(self, v):
        self.__statestack[-1]["font_family"] = v

    @property
    def font_size_pt(self):
        return self.__statestack[-1]["font_size_pt"]

    @font_size_pt.setter
    def font_size_pt(self, v):
        self.__statestack[-1]["font_size_pt"] = v

    @property
    def font_size(self):
        return self.__statestack[-1]["font_size_pt"] / self.k

    @font_size.setter
    def font_size(self, v):
        self.__statestack[-1]["font_size_pt"] = v * self.k

    @property
    def current_font(self):
        return self.__statestack[-1]["current_font"]

    @current_font.setter
    def current_font(self, v):
        self.__statestack[-1]["current_font"] = v

    @property
    def dash_pattern(self):
        return self.__statestack[-1]["dash_pattern"]

    @dash_pattern.setter
    def dash_pattern(self, v):
        self.__statestack[-1]["dash_pattern"] = v

    @property
    def line_width(self):
        return self.__statestack[-1]["line_width"]

    @line_width.setter
    def line_width(self, v):
        self.__statestack[-1]["line_width"] = v

    @property
    def text_mode(self):
        return self.__statestack[-1]["text_mode"]

    @text_mode.setter
    def text_mode(self, v):
        self.__statestack[-1]["text_mode"] = TextMode.coerce(v)

    @property
    def char_vpos(self):
        """
        Return vertical character position relative to line.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["char_vpos"]

    @char_vpos.setter
    def char_vpos(self, v):
        """
        Set vertical character position relative to line.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["char_vpos"] = CharVPos.coerce(v)

    @property
    def sub_scale(self):
        """
        Return scale factor for subscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["sub_scale"]

    @sub_scale.setter
    def sub_scale(self, v):
        """
        Set scale factor for subscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["sub_scale"] = float(v)

    @property
    def sup_scale(self):
        """
        Return scale factor for superscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["sup_scale"]

    @sup_scale.setter
    def sup_scale(self, v):
        """
        Set scale factor for superscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["sup_scale"] = float(v)

    @property
    def nom_scale(self):
        """
        Return scale factor for nominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["nom_scale"]

    @nom_scale.setter
    def nom_scale(self, v):
        """
        Set scale factor for nominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["nom_scale"] = float(v)

    @property
    def denom_scale(self):
        """
        Return scale factor for denominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["denom_scale"]

    @denom_scale.setter
    def denom_scale(self, v):
        """
        Set scale factor for denominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["denom_scale"] = float(v)

    @property
    def sub_lift(self):
        """
        Return lift factor for subscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["sub_lift"]

    @sub_lift.setter
    def sub_lift(self, v):
        """
        Set lift factor for subscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["sub_lift"] = float(v)

    @property
    def sup_lift(self):
        """
        Return lift factor for superscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["sup_lift"]

    @sup_lift.setter
    def sup_lift(self, v):
        """
        Set lift factor for superscript text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["sup_lift"] = float(v)

    @property
    def nom_lift(self):
        """
        Return lift factor for nominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["nom_lift"]

    @nom_lift.setter
    def nom_lift(self, v):
        """
        Set lift factor for nominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["nom_lift"] = float(v)

    @property
    def denom_lift(self):
        """
        Return lift factor for denominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        return self.__statestack[-1]["denom_lift"]

    @denom_lift.setter
    def denom_lift(self, v):
        """
        Set lift factor for denominator text.
        ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
        """
        self.__statestack[-1]["denom_lift"] = float(v)

    @property
    def text_shaping(self):
        return self.__statestack[-1]["text_shaping"]

    @text_shaping.setter
    def text_shaping(self, v):
        self.__statestack[-1]["text_shaping"] = v

    def font_face(self):
        """
        Return a `fpdf.fonts.FontFace` instance
        representing a subset of properties of this GraphicsState.
        """
        return FontFace(
            family=self.font_family,
            emphasis=TextEmphasis.coerce(self.font_style),
            size_pt=self.font_size_pt,
            color=(
                self.text_color if self.text_color != self.DEFAULT_TEXT_COLOR else None
            ),
            fill_color=(
                self.fill_color if self.fill_color != self.DEFAULT_FILL_COLOR else None
            ),
        )

Mixin class for managing a stack of graphics state variables.

To the subclassing library and its users, the variables look like normal instance attributes. But by the magic of properties, we can push and pop levels as needed, and users will always see and modify just the current version.

This class is mixed in by fpdf.FPDF(), and is not meant to be used directly by user code.

Subclasses

• FPDF

Class variables

var DEFAULT_DRAW_COLOR

The type of the None singleton.

var DEFAULT_FILL_COLOR

The type of the None singleton.

var DEFAULT_TEXT_COLOR

The type of the None singleton.

Instance variables

prop char_spacing

Expand source code Browse git

@property
def char_spacing(self):
    return self.__statestack[-1]["char_spacing"]

prop char_vpos

Expand source code Browse git

@property
def char_vpos(self):
    """
    Return vertical character position relative to line.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["char_vpos"]

Return vertical character position relative to line. (docs)

prop current_font

Expand source code Browse git

@property
def current_font(self):
    return self.__statestack[-1]["current_font"]

prop dash_pattern

Expand source code Browse git

@property
def dash_pattern(self):
    return self.__statestack[-1]["dash_pattern"]

prop denom_lift

Expand source code Browse git

@property
def denom_lift(self):
    """
    Return lift factor for denominator text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["denom_lift"]

Return lift factor for denominator text. (docs)

prop denom_scale

Expand source code Browse git

@property
def denom_scale(self):
    """
    Return scale factor for denominator text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["denom_scale"]

Return scale factor for denominator text. (docs)

prop draw_color

Expand source code Browse git

@property
def draw_color(self):
    return self.__statestack[-1]["draw_color"]

prop fill_color

Expand source code Browse git

@property
def fill_color(self):
    return self.__statestack[-1]["fill_color"]

prop font_family

Expand source code Browse git

@property
def font_family(self):
    return self.__statestack[-1]["font_family"]

prop font_size

Expand source code Browse git

@property
def font_size(self):
    return self.__statestack[-1]["font_size_pt"] / self.k

prop font_size_pt

Expand source code Browse git

@property
def font_size_pt(self):
    return self.__statestack[-1]["font_size_pt"]

prop font_stretching

Expand source code Browse git

@property
def font_stretching(self):
    return self.__statestack[-1]["font_stretching"]

prop font_style

Expand source code Browse git

@property
def font_style(self):
    return self.__statestack[-1]["font_style"]

prop line_width

Expand source code Browse git

@property
def line_width(self):
    return self.__statestack[-1]["line_width"]

prop nom_lift

Expand source code Browse git

@property
def nom_lift(self):
    """
    Return lift factor for nominator text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["nom_lift"]

Return lift factor for nominator text. (docs)

prop nom_scale

Expand source code Browse git

@property
def nom_scale(self):
    """
    Return scale factor for nominator text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["nom_scale"]

Return scale factor for nominator text. (docs)

prop sub_lift

Expand source code Browse git

@property
def sub_lift(self):
    """
    Return lift factor for subscript text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["sub_lift"]

Return lift factor for subscript text. (docs)

prop sub_scale

Expand source code Browse git

@property
def sub_scale(self):
    """
    Return scale factor for subscript text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["sub_scale"]

Return scale factor for subscript text. (docs)

prop sup_lift

Expand source code Browse git

@property
def sup_lift(self):
    """
    Return lift factor for superscript text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["sup_lift"]

Return lift factor for superscript text. (docs)

prop sup_scale

Expand source code Browse git

@property
def sup_scale(self):
    """
    Return scale factor for superscript text.
    ([docs](../TextStyling.html#subscript-superscript-and-fractional-numbers))
    """
    return self.__statestack[-1]["sup_scale"]

Return scale factor for superscript text. (docs)

prop text_color

Expand source code Browse git

@property
def text_color(self):
    return self.__statestack[-1]["text_color"]

prop text_mode

Expand source code Browse git

@property
def text_mode(self):
    return self.__statestack[-1]["text_mode"]

prop text_shaping

Expand source code Browse git

@property
def text_shaping(self):
    return self.__statestack[-1]["text_shaping"]

prop underline

Expand source code Browse git

@property
def underline(self):
    return self.__statestack[-1]["underline"]

Methods

def font_face(self)

Expand source code Browse git

def font_face(self):
    """
    Return a `fpdf.fonts.FontFace` instance
    representing a subset of properties of this GraphicsState.
    """
    return FontFace(
        family=self.font_family,
        emphasis=TextEmphasis.coerce(self.font_style),
        size_pt=self.font_size_pt,
        color=(
            self.text_color if self.text_color != self.DEFAULT_TEXT_COLOR else None
        ),
        fill_color=(
            self.fill_color if self.fill_color != self.DEFAULT_FILL_COLOR else None
        ),
    )

Return a FontFace instance representing a subset of properties of this GraphicsState.