Color Picker

Composer has a helper for simple and convenient usage of its new color picker inside a sidebar or extension. This helper allows to create persistent color objects that carry information for a given system color, for example the foreground color, the page's background color, table cells' background color and so on.

Create a new persistent color object

Method name	`newPersistentColorObject`
Parameters	`aColorObjectId`, a unique string identifying the color object
Return value	`null` in case of error or failure, the color object otherwise

List of predefined color object identifiers:

"TextColor" : color of the text
"PageBackgroundColor" : background color of the document
"TableBackgroundColor" : background of a table
"TableCellBackgroundColor" : background of a table cell
"BorderColor" : color of a border or outline applied to an element

Delete a persistent color object

Method name	`cleanPersistentColorObject`
Parameters	`aColorObjectId`, a unique string identifying the color object
Return value	`no return value`

Retrieve the selected color in a color object

Method name	`getCurrentColor`
Parameters	`aColorObjectId`, a unique string identifying the color object
Return value	`null` in case of error or failure (for instance if the corresponding color object does not exist), the selected color in the corresponding color object otherwise

Set the last picked color for a given color object

Method name	`setLastPickedColor`
Parameters	`aColorObjectId`, a unique string identifying the color object `aColor`, a color (see the CSS definition of a color)
Return value	`null` in case of error or failure, the color `aColor` otherwise

Show the color picker

Method name	`openColorPicker`
Parameters	`aColorObjectId`, a unique string identifying the color object ; if the color object for this identifier does not already exist, a new color object is created for that identifier `aWindowTitle,` a title for the color picker dialog `aShowTransparency`, a boolean being true if the checkbox allowing to set the color "transparent" has to be shown (for CSS backgrounds for instance)
Return value	`null` in case of error or failure, the color object otherwise

It is possible to check if the color picker was closed by the user on a Cancel action using the following method:

Check if the color picker was cancelled

Method name	`isCancelled`
Parameters	`aColorObjectId`, a unique string identifying the color object
Return value	`returns a boolean is the last color picked shown for the color object identifier was cancelled ; if there is no color object for this identifier, an exception NS_ERROR_NULL_POINTER is thrown`

Example

const kTEMPLATE_COLUMN_BG_COLOR = "TemplateColumnBgColor";
var colorHelper = window.top.ColorPickerHelper;
if (colorHelper.newPersistentColorObject(kTEMPLATE_COLUMN_BG_COLOR))
{
  colorHelper.openColorPicker( kTEMPLATE_COLUMN_BG_COLOR,
                               "Set the background color for the column",
                               true);
  if (colorHelper.isCancelled(kTEMPLATE_COLUMN_BG_COLOR))
    return;
  SetTemplateBgColor(colorHelper.getCurrentColor(kTEMPLATE_COLUMN_BG_COLOR));
}