ladybird/Libraries/LibWeb/Editing/ExecCommand.cpp
2024-12-03 00:18:03 +01:00

232 lines
10 KiB
C++

/*
* Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/Range.h>
#include <LibWeb/Editing/CommandNames.h>
#include <LibWeb/Editing/Commands.h>
#include <LibWeb/Editing/Internal/Algorithms.h>
#include <LibWeb/Selection/Selection.h>
namespace Web::DOM {
// https://w3c.github.io/editing/docs/execCommand/#execcommand()
bool Document::exec_command(FlyString const& command, [[maybe_unused]] bool show_ui, String const& value)
{
// 1. If only one argument was provided, let show UI be false.
// 2. If only one or two arguments were provided, let value be the empty string.
// NOTE: these steps are dealt by the default values for both show_ui and value
// 3. If command is not supported or not enabled, return false.
// NOTE: query_command_enabled() also checks if command is supported
if (!query_command_enabled(command))
return false;
// 4. If command is not in the Miscellaneous commands section:
//
// We don't fire events for copy/cut/paste/undo/redo/selectAll because they should all have
// their own events. We don't fire events for styleWithCSS/useCSS because it's not obvious
// where to fire them, or why anyone would want them. We don't fire events for unsupported
// commands, because then if they became supported and were classified with the miscellaneous
// events, we'd have to stop firing events for consistency's sake.
//
// AD-HOC: The defaultParagraphSeparator command is also in the Miscellaneous commands section
if (command != Editing::CommandNames::defaultParagraphSeparator
&& command != Editing::CommandNames::redo
&& command != Editing::CommandNames::selectAll
&& command != Editing::CommandNames::styleWithCSS
&& command != Editing::CommandNames::undo
&& command != Editing::CommandNames::useCSS) {
// FIXME: 1. Let affected editing host be the editing host that is an inclusive ancestor of the
// active range's start node and end node, and is not the ancestor of any editing host
// that is an inclusive ancestor of the active range's start node and end node.
// FIXME: 2. Fire an event named "beforeinput" at affected editing host using InputEvent, with its
// bubbles and cancelable attributes initialized to true, and its data attribute
// initialized to null.
// FIXME: 3. If the value returned by the previous step is false, return false.
// 4. If command is not enabled, return false.
//
// We have to check again whether the command is enabled, because the beforeinput handler
// might have done something annoying like getSelection().removeAllRanges().
if (!query_command_enabled(command))
return false;
// FIXME: 5. Let affected editing host be the editing host that is an inclusive ancestor of the
// active range's start node and end node, and is not the ancestor of any editing host
// that is an inclusive ancestor of the active range's start node and end node.
//
// This new affected editing host is what we'll fire the input event at in a couple of
// lines. We want to compute it beforehand just to be safe: bugs in the command action
// might remove the selection or something bad like that, and we don't want to have to
// handle it later. We recompute it after the beforeinput event is handled so that if the
// handler moves the selection to some other editing host, the input event will be fired
// at the editing host that was actually affected.
}
// 5. Take the action for command, passing value to the instructions as an argument.
auto optional_command = Editing::find_command_definition(command);
VERIFY(optional_command.has_value());
auto const& command_definition = optional_command.release_value();
auto command_result = command_definition.action(*this, value);
// 6. If the previous step returned false, return false.
if (!command_result)
return false;
// FIXME: 7. If the action modified DOM tree, then fire an event named "input" at affected editing host
// using InputEvent, with its isTrusted and bubbles attributes initialized to true, inputType
// attribute initialized to the mapped value of command, and its data attribute initialized
// to null.
// 8. Return true.
return true;
}
// https://w3c.github.io/editing/docs/execCommand/#querycommandenabled()
bool Document::query_command_enabled(FlyString const& command)
{
// 2. Return true if command is both supported and enabled, false otherwise.
if (!query_command_supported(command))
return false;
// https://w3c.github.io/editing/docs/execCommand/#enabled
// Among commands defined in this specification, those listed in Miscellaneous commands are always enabled, except
// for the cut command and the paste command.
// NOTE: cut and paste are actually in the Clipboard commands section
if (command.is_one_of(
Editing::CommandNames::defaultParagraphSeparator,
Editing::CommandNames::redo,
Editing::CommandNames::selectAll,
Editing::CommandNames::styleWithCSS,
Editing::CommandNames::undo,
Editing::CommandNames::useCSS))
return true;
// The other commands defined here are enabled if the active range is not null,
auto selection = get_selection();
if (!selection)
return false;
auto active_range = selection->range();
if (!active_range)
return false;
// its start node is either editable or an editing host,
auto start_node = active_range->start_container();
if (!start_node->is_editable() && !Editing::is_editing_host(start_node))
return false;
// FIXME: the editing host of its start node is not an EditContext editing host,
auto start_node_editing_host = Editing::editing_host_of_node(start_node);
// its end node is either editable or an editing host,
auto& end_node = *active_range->end_container();
if (!end_node.is_editable() && !Editing::is_editing_host(end_node))
return false;
// FIXME: the editing host of its end node is not an EditContext editing host,
// FIXME: and there is some editing host that is an inclusive ancestor of both its start node and its
// end node.
// NOTE: Commands can define additional conditions for being enabled, and currently the only condition mentioned in
// the spec is that certain commands must not be enabled if the editing host is in the plaintext-only state.
if (is<HTML::HTMLElement>(start_node_editing_host.ptr())
&& static_cast<HTML::HTMLElement&>(*start_node_editing_host).content_editable_state() == HTML::ContentEditableState::PlaintextOnly
&& command.is_one_of(
Editing::CommandNames::backColor,
Editing::CommandNames::bold,
Editing::CommandNames::createLink,
Editing::CommandNames::fontName,
Editing::CommandNames::fontSize,
Editing::CommandNames::foreColor,
Editing::CommandNames::hiliteColor,
Editing::CommandNames::indent,
Editing::CommandNames::insertHorizontalRule,
Editing::CommandNames::insertImage,
Editing::CommandNames::insertOrderedList,
Editing::CommandNames::insertUnorderedList,
Editing::CommandNames::italic,
Editing::CommandNames::justifyCenter,
Editing::CommandNames::justifyFull,
Editing::CommandNames::justifyLeft,
Editing::CommandNames::justifyRight,
Editing::CommandNames::outdent,
Editing::CommandNames::removeFormat,
Editing::CommandNames::strikethrough,
Editing::CommandNames::subscript,
Editing::CommandNames::superscript,
Editing::CommandNames::underline,
Editing::CommandNames::unlink))
return false;
return true;
}
// https://w3c.github.io/editing/docs/execCommand/#querycommandindeterm()
bool Document::query_command_indeterm(FlyString const& command)
{
// 1. If command is not supported or has no indeterminacy, return false.
auto optional_command = Editing::find_command_definition(command);
if (!optional_command.has_value())
return false;
auto const& command_definition = optional_command.value();
if (!command_definition.indeterminate)
return false;
// 2. Return true if command is indeterminate, otherwise false.
return command_definition.indeterminate(*this);
}
// https://w3c.github.io/editing/docs/execCommand/#querycommandstate()
bool Document::query_command_state(FlyString const& command)
{
// 1. If command is not supported or has no state, return false.
auto optional_command = Editing::find_command_definition(command);
if (!optional_command.has_value())
return false;
auto const& command_definition = optional_command.release_value();
if (!command_definition.state)
return false;
// FIXME: 2. If the state override for command is set, return it.
// 3. Return true if command's state is true, otherwise false.
return command_definition.state(*this);
}
// https://w3c.github.io/editing/docs/execCommand/#querycommandsupported()
bool Document::query_command_supported(FlyString const& command)
{
// When the queryCommandSupported(command) method on the Document interface is invoked, the
// user agent must return true if command is supported and available within the current script
// on the current site, and false otherwise.
return Editing::find_command_definition(command).has_value();
}
// https://w3c.github.io/editing/docs/execCommand/#querycommandvalue()
String Document::query_command_value(FlyString const& command)
{
// 1. If command is not supported or has no value, return the empty string.
auto optional_command = Editing::find_command_definition(command);
if (!optional_command.has_value())
return {};
auto const& command_definition = optional_command.release_value();
if (!command_definition.value)
return {};
// FIXME: 2. If command is "fontSize" and its value override is set, convert the value override to an
// integer number of pixels and return the legacy font size for the result.
// FIXME: 3. If the value override for command is set, return it.
// 4. Return command's value.
return command_definition.value(*this);
}
}