Module gears.color - awesome API documentation

# Module `gears.color`

This module simplifies the creation of cairo pattern objects.

In most places in awesome where a color is needed, the provided argument is passed to gears.color, which actually calls create_pattern and creates a pattern from a given string or table.

This function can create solid, linear, radial and png patterns.

A simple example for a solid pattern is a hexadecimal color specification. For example `#ff8000` creates a solid pattern with 100% red, 50% green and 0% blue. Limited support for named colors (`red`) is also provided.

In general, patterns are specified as strings formatted as `"type:arguments"`. `"arguments"` is specific to the pattern being used. For example, one can use:

    "radial:50,50,10:55,55,30:0,#ff0000:0.5,#00ff00:1,#0000ff"

The above will call create_radial_pattern with the provided string, after stripping the `radial:` prefix.

Alternatively, patterns can be specified via tables. In this case, the table's 'type' member specifies the type. For example:

    {
      type = "radial",
      from = { 50, 50, 10 },
      to = { 55, 55, 30 },
      stops = { { 0, "#ff0000" }, { 0.5, "#00ff00" }, { 1, "#0000ff" } }
    }

Any argument that cannot be understood is passed to create_solid_pattern.

Please note that you MUST NOT modify the returned pattern, for example by calling :set_matrix() on it, because this function uses a cache and your changes could thus have unintended side effects. Use create_pattern_uncached if you need to modify the returned pattern.

### See also:

- create_pattern_uncached
- create_solid_pattern
- create_png_pattern
- create_linear_pattern
- create_radial_pattern

### Info:

- Copyright: 2010 Uli Schlachter
- Author: Uli Schlachter

## Functions

returns... (col) |
parse_color (col) | Parse a HTML-color.
create_solid_pattern (col) | Create a solid pattern
create_png_pattern (file) | Create an image pattern from a png file
create_linear_pattern (arg) | Create a linear pattern object.
create_radial_pattern (arg) | Create a radial pattern object.
create_pattern_uncached (col) | Create a pattern from a given string.
create_pattern (col) | Create a pattern from a given string, same as gears.color.
create_opaque_pattern (col) | Check if a pattern is opaque.
recolor_image (image, new_color) | Fill non-transparent area of an image with a given color.
ensure_pango_color (check_color, fallback) | Get a valid color for Pango markup

## Tables

types | Mapping of all supported color types.

## Fields

transparent | No color

## Functions

Methods

returns... (col)
  - col string The string describing the pattern.

  ### Returns:

  a cairo pattern object
parse_color (col)
  Parse a HTML-color. This function can parse colors like `#rrggbb` and `#rrggbbaa` and also `red`. Max 4 chars per channel.
  - col The color to parse

  ### Returns:

  table 4 values representing color in RGBA format (each of them in [0, 1] range) or nil if input is incorrect.

  ### Usage:

      -- This will return 0, 1, 0, 1
       gears.color.parse_color("#00ff00ff")

create_solid_pattern (col)
  Create a solid pattern
  - col The color for the pattern

  ### Returns:

  A cairo pattern object
create_png_pattern (file)
  Create an image pattern from a png file
  - file The filename of the file

  ### Returns:

  a cairo pattern object
create_linear_pattern (arg)
  Create a linear pattern object. The pattern is created from a string. This string should have the following form: `"x0, y0:x1, y1:<stops>"` Alternatively, the pattern can be specified as a table:

      { type = "linear", from = { x0, y0 }, to = { x1, y1 },
        stops = { <stops> } }

  `x0,y0` and `x1,y1` are the start and stop point of the pattern. For the explanation of `<stops>`, see color.create_pattern.

  - arg string or table The argument describing the pattern.

  ### Returns:

  a cairo pattern object
create_radial_pattern (arg)
  Create a radial pattern object. The pattern is created from a string. This string should have the following form: `"x0, y0, r0:x1, y1, r1:<stops>"` Alternatively, the pattern can be specified as a table:

      { type = "radial", from = { x0, y0, r0 }, to = { x1, y1, r1 },
        stops = { <stops> } }

  `x0,y0` and `x1,y1` are the start and stop point of the pattern. `r0` and `r1` are the radii of the start / stop circle. For the explanation of `<stops>`, see color.create_pattern.

  - arg string or table The argument describing the pattern

  ### Returns:

  a cairo pattern object
create_pattern_uncached (col)
  Create a pattern from a given string. For full documentation of this function, please refer to color.create_pattern. The difference between color.create_pattern and this function is that this function does not insert the generated objects into the pattern cache. Thus, you are allowed to modify the returned object.
  - col The string describing the pattern.

  ### Returns:

  a cairo pattern object

  ### See also:

  create_pattern
create_pattern (col)
  Create a pattern from a given string, same as gears.color.
  - col

  ### See also:

  gears.color
create_opaque_pattern (col)
  Check if a pattern is opaque. A pattern is transparent if the background on which it gets drawn (with operator OVER) doesn't influence the visual result.
  - col An argument that create_pattern accepts.

  ### Returns:

  The pattern if it is surely opaque, else nil
recolor_image (image, new_color)
  Fill non-transparent area of an image with a given color.
  - image Image or path to it.
  - new_color New color.

  ### Returns:

  Recolored image.
ensure_pango_color (check_color, fallback)
  Get a valid color for Pango markup
  - check_color The color to check.
  - fallback string The color to return if the first is invalid. (default: black)

  ### Returns:

  string color if it is valid, else fallback.

## Tables

types
  Mapping of all supported color types. New entries can be added.

  ### Fields:

  - solid
  - png
  - linear
  - radial

## Fields

transparent
  No color

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