Package ch.bailu.gtk.pango

Class Renderer

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.gobject.Object
ch.bailu.gtk.pango.Renderer
All Implemented Interfaces:
PointerInterface
public class Renderer extends Object
`PangoRenderer` is a base class for objects that can render text
provided as `PangoGlyphString` or `PangoLayout`.

By subclassing `PangoRenderer` and overriding operations such as
@draw_glyphs and @draw_rectangle, renderers for particular font
backends and destinations can be created.

https://docs.gtk.org/Pango/class.Renderer.html

  • Constructor Details

  • Method Details

    • getClassHandler

      public static ClassHandler getClassHandler()

    • activate

      public void activate()
      Does initial setup before rendering operations on @renderer.

      [method@Pango.Renderer.deactivate] should be called when done drawing.
      Calls such as [method@Pango.Renderer.draw_layout] automatically
      activate the layout before drawing on it.

      Calls to [method@Pango.Renderer.activate] and
      [method@Pango.Renderer.deactivate] can be nested and the
      renderer will only be initialized and deinitialized once.

    • deactivate

      public void deactivate()
      Cleans up after rendering operations on @renderer.

      See docs for [method@Pango.Renderer.activate].

    • drawErrorUnderline

      public void drawErrorUnderline(int x, int y, int width, int height)
      Draw a squiggly line that approximately covers the given rectangle
      in the style of an underline used to indicate a spelling error.

      The width of the underline is rounded to an integer number
      of up/down segments and the resulting rectangle is centered
      in the original rectangle.

      This should be called while @renderer is already active.
      Use [method@Pango.Renderer.activate] to activate a renderer.
      Parameters:
      x - X coordinate of underline, in Pango units in user coordinate system
      y - Y coordinate of underline, in Pango units in user coordinate system
      width - width of underline, in Pango units in user coordinate system
      height - height of underline, in Pango units in user coordinate system

    • drawGlyphItem

      public void drawGlyphItem(@Nullable Str text, @Nonnull GlyphItem glyph_item, int x, int y)
      Draws the glyphs in @glyph_item with the specified `PangoRenderer`,
      embedding the text associated with the glyphs in the output if the
      output format supports it.

      This is useful for rendering text in PDF.

      Note that this method does not handle attributes in @glyph_item.
      If you want colors, shapes and lines handled automatically according
      to those attributes, you need to use pango_renderer_draw_layout_line()
      or pango_renderer_draw_layout().

      Note that @text is the start of the text for layout, which is then
      indexed by `glyph_item->item->offset`.

      If @text is %NULL, this simply calls [method@Pango.Renderer.draw_glyphs].

      The default implementation of this method simply falls back to
      [method@Pango.Renderer.draw_glyphs].
      Parameters:
      text - the UTF-8 text that @glyph_item refers to
      glyph_item - a `PangoGlyphItem`
      x - X position of left edge of baseline, in user space coordinates in Pango units
      y - Y position of left edge of baseline, in user space coordinates in Pango units

    • drawGlyphItem

      public void drawGlyphItem(String text, @Nonnull GlyphItem glyph_item, int x, int y)
      Draws the glyphs in @glyph_item with the specified `PangoRenderer`,
      embedding the text associated with the glyphs in the output if the
      output format supports it.

      This is useful for rendering text in PDF.

      Note that this method does not handle attributes in @glyph_item.
      If you want colors, shapes and lines handled automatically according
      to those attributes, you need to use pango_renderer_draw_layout_line()
      or pango_renderer_draw_layout().

      Note that @text is the start of the text for layout, which is then
      indexed by `glyph_item->item->offset`.

      If @text is %NULL, this simply calls [method@Pango.Renderer.draw_glyphs].

      The default implementation of this method simply falls back to
      [method@Pango.Renderer.draw_glyphs].
      Parameters:
      text - the UTF-8 text that @glyph_item refers to
      glyph_item - a `PangoGlyphItem`
      x - X position of left edge of baseline, in user space coordinates in Pango units
      y - Y position of left edge of baseline, in user space coordinates in Pango units

    • drawGlyphs

      public void drawGlyphs(@Nonnull Font font, @Nonnull GlyphString glyphs, int x, int y)
      Draws the glyphs in @glyphs with the specified `PangoRenderer`.
      Parameters:
      font - a `PangoFont`
      glyphs - a `PangoGlyphString`
      x - X position of left edge of baseline, in user space coordinates in Pango units.
      y - Y position of left edge of baseline, in user space coordinates in Pango units.

    • drawLayout

      public void drawLayout(@Nonnull Layout layout, int x, int y)
      Draws @layout with the specified `PangoRenderer`.

      This is equivalent to drawing the lines of the layout, at their
      respective positions relative to @x, @y.
      Parameters:
      layout - a `PangoLayout`
      x - X position of left edge of baseline, in user space coordinates in Pango units.
      y - Y position of left edge of baseline, in user space coordinates in Pango units.

    • drawLayoutLine

      public void drawLayoutLine(@Nonnull LayoutLine line, int x, int y)
      Draws @line with the specified `PangoRenderer`.

      This draws the glyph items that make up the line, as well as
      shapes, backgrounds and lines that are specified by the attributes
      of those items.
      Parameters:
      line - a `PangoLayoutLine`
      x - X position of left edge of baseline, in user space coordinates in Pango units.
      y - Y position of left edge of baseline, in user space coordinates in Pango units.

    • drawRectangle

      public void drawRectangle(int part, int x, int y, int width, int height)
      Draws an axis-aligned rectangle in user space coordinates with the
      specified `PangoRenderer`.

      This should be called while @renderer is already active.
      Use [method@Pango.Renderer.activate] to activate a renderer.
      Parameters:
      part - type of object this rectangle is part of
      x - X position at which to draw rectangle, in user space coordinates in Pango units
      y - Y position at which to draw rectangle, in user space coordinates in Pango units
      width - width of rectangle in Pango units
      height - height of rectangle in Pango units

    • drawTrapezoid

      public void drawTrapezoid(int part, double y1_, double x11, double x21, double y2, double x12, double x22)
      Draws a trapezoid with the parallel sides aligned with the X axis
      using the given `PangoRenderer`; coordinates are in device space.
      Parameters:
      part - type of object this trapezoid is part of
      y1_ - Y coordinate of top of trapezoid
      x11 - X coordinate of left end of top of trapezoid
      x21 - X coordinate of right end of top of trapezoid
      y2 - Y coordinate of bottom of trapezoid
      x12 - X coordinate of left end of bottom of trapezoid
      x22 - X coordinate of right end of bottom of trapezoid

    • getAlpha

      public int getAlpha(int part)
      Gets the current alpha for the specified part.
      Parameters:
      part - the part to get the alpha for
      Returns:
      the alpha for the specified part, or 0 if it hasn't been set and should be inherited from the environment.

    • getColor

      public Color getColor(int part)
      Gets the current rendering color for the specified part.
      Parameters:
      part - the part to get the color for
      Returns:
      the color for the specified part, or %NULL if it hasn't been set and should be inherited from the environment.

    • getLayout

      public Layout getLayout()
      Gets the layout currently being rendered using @renderer.

      Calling this function only makes sense from inside a subclass's
      methods, like in its draw_shape vfunc, for example.

      The returned layout should not be modified while still being
      rendered.
      Returns:
      the layout, or %NULL if no layout is being rendered using @renderer at this time.

    • getLayoutLine

      public LayoutLine getLayoutLine()
      Gets the layout line currently being rendered using @renderer.

      Calling this function only makes sense from inside a subclass's
      methods, like in its draw_shape vfunc, for example.

      The returned layout line should not be modified while still being
      rendered.
      Returns:
      the layout line, or %NULL if no layout line is being rendered using @renderer at this time.

    • getMatrix

      public Matrix getMatrix()
      Gets the transformation matrix that will be applied when
      rendering.

      See [method@Pango.Renderer.set_matrix].
      Returns:
      the matrix, or %NULL if no matrix has been set (which is the same as the identity matrix). The returned matrix is owned by Pango and must not be modified or freed.

    • partChanged

      public void partChanged(int part)
      Informs Pango that the way that the rendering is done
      for @part has changed.

      This should be called if the rendering changes in a way that would
      prevent multiple pieces being joined together into one drawing call.
      For instance, if a subclass of `PangoRenderer` was to add a stipple
      option for drawing underlines, it needs to call

      ```
      pango_renderer_part_changed (render, PANGO_RENDER_PART_UNDERLINE);
      ```

      When the stipple changes or underlines with different stipples
      might be joined together. Pango automatically calls this for
      changes to colors. (See [method@Pango.Renderer.set_color])
      Parameters:
      part - the part for which rendering has changed.

    • setAlpha

      public void setAlpha(int part, int alpha)
      Sets the alpha for part of the rendering.

      Note that the alpha may only be used if a color is
      specified for @part as well.
      Parameters:
      part - the part to set the alpha for
      alpha - an alpha value between 1 and 65536, or 0 to unset the alpha

    • setColor

      public void setColor(int part, @Nullable Color color)
      Sets the color for part of the rendering.

      Also see [method@Pango.Renderer.set_alpha].
      Parameters:
      part - the part to change the color of
      color - the new color or %NULL to unset the current color

    • setMatrix

      public void setMatrix(@Nullable Matrix matrix)
      Sets the transformation matrix that will be applied when rendering.
      Parameters:
      matrix - a `PangoMatrix`, or %NULL to unset any existing matrix (No matrix set is the same as setting the identity matrix.)

    • getTypeID

      public static long getTypeID()

    • getParentTypeID

      public static long getParentTypeID()

    • getTypeSize

      public static TypeSystem.TypeSize getTypeSize()

    • getParentTypeSize

      public static TypeSystem.TypeSize getParentTypeSize()

    • getInstanceSize

      public static int getInstanceSize()