Package ch.bailu.gtk.gtk

Class Scale

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.gobject.Object
ch.bailu.gtk.gobject.InitiallyUnowned
ch.bailu.gtk.gtk.Widget
ch.bailu.gtk.gtk.Range
ch.bailu.gtk.gtk.Scale
All Implemented Interfaces:
PointerInterface
public class Scale extends Range
A `GtkScale` is a slider control used to select a numeric value.

![An example GtkScale](scales.png)

To use it, you’ll probably want to investigate the methods on its base
class, [class@GtkRange], in addition to the methods for `GtkScale` itself.
To set the value of a scale, you would normally use [method@Gtk.Range.set_value].
To detect changes to the value, you would normally use the
[signal@Gtk.Range::value-changed] signal.

Note that using the same upper and lower bounds for the `GtkScale` (through
the `GtkRange` methods) will hide the slider itself. This is useful for
applications that want to show an undeterminate value on the scale, without
changing the layout of the application (such as movie or music players).

# GtkScale as GtkBuildable

`GtkScale` supports a custom <marks> element, which can contain multiple
<mark\> elements. The “value” and “position” attributes have the same
meaning as [method@Gtk.Scale.add_mark] parameters of the same name. If
the element is not empty, its content is taken as the markup to show at
the mark. It can be translated with the usual ”translatable” and
“context” attributes.

# CSS nodes

```
scale[.fine-tune][.marks-before][.marks-after]
├── [value][.top][.right][.bottom][.left]
├── marks.top
│ ├── mark
│ ┊ ├── [label]
│ ┊ ╰── indicator
┊ ┊
│ ╰── mark
├── marks.bottom
│ ├── mark
│ ┊ ├── indicator
│ ┊ ╰── [label]
┊ ┊
│ ╰── mark
╰── trough
├── [fill]
├── [highlight]
╰── slider
```

`GtkScale` has a main CSS node with name scale and a subnode for its contents,
with subnodes named trough and slider.

The main node gets the style class .fine-tune added when the scale is in
'fine-tuning' mode.

If the scale has an origin (see [method@Gtk.Scale.set_has_origin]), there is
a subnode with name highlight below the trough node that is used for rendering
the highlighted part of the trough.

If the scale is showing a fill level (see [method@Gtk.Range.set_show_fill_level]),
there is a subnode with name fill below the trough node that is used for
rendering the filled in part of the trough.

If marks are present, there is a marks subnode before or after the trough
node, below which each mark gets a node with name mark. The marks nodes get
either the .top or .bottom style class.

The mark node has a subnode named indicator. If the mark has text, it also
has a subnode named label. When the mark is either above or left of the
scale, the label subnode is the first when present. Otherwise, the indicator
subnode is the first.

The main CSS node gets the 'marks-before' and/or 'marks-after' style classes
added depending on what marks are present.

If the scale is displaying the value (see [property@Gtk.Scale:draw-value]),
there is subnode with name value. This node will get the .top or .bottom style
classes similar to the marks node.

# Accessibility

`GtkScale` uses the %GTK_ACCESSIBLE_ROLE_SLIDER role.

https://docs.gtk.org/gtk4/class.Scale.html

  • Constructor Details

    • Scale

      public Scale(PointerContainer pointer)

    • Scale

      public Scale(int orientation, @Nullable Adjustment adjustment)
      Creates a new `GtkScale`.
      Parameters:
      orientation - the scale’s orientation.
      adjustment - the [class@Gtk.Adjustment] which sets the range of the scale, or %NULL to create a new adjustment.

  • Method Details

    • getClassHandler

      public static ClassHandler getClassHandler()

    • newWithRangeScale

      public static Scale newWithRangeScale(int orientation, double min, double max, double step)
      Creates a new scale widget with a range from @min to @max.

      The returns scale will have the given orientation and will let the
      user input a number between @min and @max (including @min and @max)
      with the increment @step. @step must be nonzero; it’s the distance
      the slider moves when using the arrow keys to adjust the scale
      value.

      Note that the way in which the precision is derived works best if
      @step is a power of ten. If the resulting precision is not suitable
      for your needs, use [method@Gtk.Scale.set_digits] to correct it.
      Parameters:
      orientation - the scale’s orientation.
      min - minimum value
      max - maximum value
      step - step increment (tick size) used with keyboard shortcuts
      Returns:
      a new `GtkScale`

    • addMark

      public void addMark(double value, int position, @Nullable Str markup)
      Adds a mark at @value.

      A mark is indicated visually by drawing a tick mark next to the scale,
      and GTK makes it easy for the user to position the scale exactly at the
      marks value.

      If @markup is not %NULL, text is shown next to the tick mark.

      To remove marks from a scale, use [method@Gtk.Scale.clear_marks].
      Parameters:
      value - the value at which the mark is placed, must be between the lower and upper limits of the scales’ adjustment
      position - where to draw the mark. For a horizontal scale, %GTK_POS_TOP and %GTK_POS_LEFT are drawn above the scale, anything else below. For a vertical scale, %GTK_POS_LEFT and %GTK_POS_TOP are drawn to the left of the scale, anything else to the right.
      markup - Text to be shown at the mark, using Pango markup

    • addMark

      public void addMark(double value, int position, String markup)
      Adds a mark at @value.

      A mark is indicated visually by drawing a tick mark next to the scale,
      and GTK makes it easy for the user to position the scale exactly at the
      marks value.

      If @markup is not %NULL, text is shown next to the tick mark.

      To remove marks from a scale, use [method@Gtk.Scale.clear_marks].
      Parameters:
      value - the value at which the mark is placed, must be between the lower and upper limits of the scales’ adjustment
      position - where to draw the mark. For a horizontal scale, %GTK_POS_TOP and %GTK_POS_LEFT are drawn above the scale, anything else below. For a vertical scale, %GTK_POS_LEFT and %GTK_POS_TOP are drawn to the left of the scale, anything else to the right.
      markup - Text to be shown at the mark, using Pango markup

    • clearMarks

      public void clearMarks()
      Removes any marks that have been added.

    • getDigits

      public int getDigits()
      Gets the number of decimal places that are displayed in the value.
      Returns:
      the number of decimal places that are displayed

    • getDrawValue

      public boolean getDrawValue()
      Returns whether the current value is displayed as a string
      next to the slider.
      Returns:
      whether the current value is displayed as a string

    • getHasOrigin

      public boolean getHasOrigin()
      Returns whether the scale has an origin.
      Returns:
      %TRUE if the scale has an origin.

    • getLayout

      public Layout getLayout()
      Gets the `PangoLayout` used to display the scale.

      The returned object is owned by the scale so does not need
      to be freed by the caller.
      Returns:
      the [class@Pango.Layout] for this scale, or %NULL if the [property@GtkScale:draw-value] property is %FALSE.

    • getLayoutOffsets

      public void getLayoutOffsets(@Nullable Int x, @Nullable Int y)
      Obtains the coordinates where the scale will draw the
      `PangoLayout` representing the text in the scale.

      Remember when using the `PangoLayout` function you need to
      convert to and from pixels using `PANGO_PIXELS()` or `PANGO_SCALE`.

      If the [property@GtkScale:draw-value] property is %FALSE, the return
      values are undefined.
      Parameters:
      x - location to store X offset of layout
      y - location to store Y offset of layout

    • getValuePos

      public int getValuePos()
      Gets the position in which the current value is displayed.
      Returns:
      the position in which the current value is displayed

    • setDigits

      public void setDigits(int digits)
      Sets the number of decimal places that are displayed in the value.

      Also causes the value of the adjustment to be rounded to this number
      of digits, so the retrieved value matches the displayed one, if
      [property@GtkScale:draw-value] is %TRUE when the value changes. If
      you want to enforce rounding the value when [property@GtkScale:draw-value]
      is %FALSE, you can set [property@GtkRange:round-digits] instead.

      Note that rounding to a small number of digits can interfere with
      the smooth autoscrolling that is built into `GtkScale`. As an alternative,
      you can use [method@Gtk.Scale.set_format_value_func] to format the displayed
      value yourself.
      Parameters:
      digits - the number of decimal places to display, e.g. use 1 to display 1.0, 2 to display 1.00, etc

    • setDrawValue

      public void setDrawValue(boolean draw_value)
      Specifies whether the current value is displayed as a string next
      to the slider.
      Parameters:
      draw_value - %TRUE to draw the value

    • setFormatValueFunc

      public void setFormatValueFunc(Scale.OnScaleFormatValueFunc func, @Nullable Pointer user_data, Scale.OnDestroyNotify destroy_notify)
      @func allows you to change how the scale value is displayed.

      The given function will return an allocated string representing
      @value. That string will then be used to display the scale's value.

      If #NULL is passed as @func, the value will be displayed on
      its own, rounded according to the value of the
      [property@GtkScale:digits] property.
      Parameters:
      func - function that formats the value
      user_data - user data to pass to @func
      destroy_notify - destroy function for @user_data

    • setHasOrigin

      public void setHasOrigin(boolean has_origin)
      Sets whether the scale has an origin.

      If [property@GtkScale:has-origin] is set to %TRUE (the default),
      the scale will highlight the part of the trough between the origin
      (bottom or left side) and the current value.
      Parameters:
      has_origin - %TRUE if the scale has an origin

    • setValuePos

      public void setValuePos(int pos)
      Sets the position in which the current value is displayed.
      Parameters:
      pos - the position in which the current value is displayed

    • asAccessible

      public Accessible asAccessible()
      Implements interface Accessible. Call this to get access to interface functions.
      Overrides:
      asAccessible in class Range
      Returns:
      Accessible

    • asBuildable

      public Buildable asBuildable()
      Implements interface Buildable. Call this to get access to interface functions.
      Overrides:
      asBuildable in class Range
      Returns:
      Buildable

    • asConstraintTarget

      public ConstraintTarget asConstraintTarget()
      Implements interface ConstraintTarget. Call this to get access to interface functions.
      Overrides:
      asConstraintTarget in class Range
      Returns:
      ConstraintTarget

    • asOrientable

      public Orientable asOrientable()
      Implements interface Orientable. Call this to get access to interface functions.
      Overrides:
      asOrientable in class Range
      Returns:
      Orientable

    • 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()