/*
* This source file is part of RmlUi, the HTML/CSS Interface Middleware
*
* For the latest information, see http://github.com/mikke89/RmlUi
*
* Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd
* Copyright (c) 2019-2023 The RmlUi Team, and contributors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*/
#include "ElementHandle.h"
#include "../../Include/RmlUi/Core/ComputedValues.h"
#include "../../Include/RmlUi/Core/Context.h"
#include "../../Include/RmlUi/Core/ElementDocument.h"
#include "../../Include/RmlUi/Core/ElementUtilities.h"
#include "../../Include/RmlUi/Core/Event.h"
#include "../../Include/RmlUi/Core/Property.h"
namespace Rml {
ElementHandle::ElementHandle(const String& tag) : Element(tag), drag_start(0, 0)
{
// Make sure we can be dragged!
SetProperty(PropertyId::Drag, Property(Style::Drag::Drag));
move_target = nullptr;
size_target = nullptr;
initialised = false;
}
ElementHandle::~ElementHandle() {}
void ElementHandle::OnAttributeChange(const ElementAttributes& changed_attributes)
{
Element::OnAttributeChange(changed_attributes);
// Reset initialised state if the move or size targets have changed.
if (changed_attributes.find("move_target") != changed_attributes.end() || changed_attributes.find("size_target") != changed_attributes.end())
{
initialised = false;
move_target = nullptr;
size_target = nullptr;
}
}
void ElementHandle::ProcessDefaultAction(Event& event)
{
Element::ProcessDefaultAction(event);
if (event.GetTargetElement() == this)
{
// Lazy initialisation.
if (!initialised && GetOwnerDocument())
{
String move_target_name = GetAttribute("move_target", "");
if (!move_target_name.empty())
move_target = GetElementById(move_target_name);
String size_target_name = GetAttribute("size_target", "");
if (!size_target_name.empty())
size_target = GetElementById(size_target_name);
initialised = true;
}
// Set any auto margins to their current value, since auto-margins may affect the size and position of an element.
auto SetDefiniteMargins = [](Element* element, const ComputedValues& computed) {
auto SetDefiniteMargin = [](Element* element, PropertyId margin_id, BoxEdge edge) {
element->SetProperty(margin_id, Property(Math::Round(element->GetBox().GetEdge(BoxArea::Margin, edge)), Unit::PX));
};
using Style::Margin;
if (computed.margin_top().type == Margin::Auto)
SetDefiniteMargin(element, PropertyId::MarginTop, BoxEdge::Top);
if (computed.margin_right().type == Margin::Auto)
SetDefiniteMargin(element, PropertyId::MarginRight, BoxEdge::Right);
if (computed.margin_bottom().type == Margin::Auto)
SetDefiniteMargin(element, PropertyId::MarginBottom, BoxEdge::Bottom);
if (computed.margin_left().type == Margin::Auto)
SetDefiniteMargin(element, PropertyId::MarginLeft, BoxEdge::Left);
};
// The following table lists the expected behavior for each combination of definite (non-auto) properties:
//
// Definite properties | Move | Size
// ---------------------|-------------------------|--------------------------
// (none) | left += dx | width += dx
// left | left += dx | width += dx
// right | right -= dx | right -= dx; width += dx
// width | left += dx | width += dx
// left & right | left += dx; right -= dx | right -= dx
// left & width | left += dx; | width += dx
// right & width | right -= dx | right -= dx; width += dx
// right & width | right -= dx | right -= dx; width += dx
// left & right & width | left += dx; | width += dx
//
// For simplicity, this table only specifies the horizontal direction. The same behavior applies for the
// corresponding properties in the vertical direction. For now, we assume that the handle is anchored to the
// bottom-right corner of the target element.
if (event == EventId::Dragstart)
{
Context* context = GetContext();
drag_start = event.GetUnprojectedMouseScreenPos();
if (move_target && context)
{
using namespace Style;
const Box& parent_box =
move_target->GetOffsetParent() ? move_target->GetOffsetParent()->GetBox() : context->GetRootElement()->GetBox();
const Vector2f containing_block = move_target->GetContainingBlock();
const Box& box = move_target->GetBox();
const auto& computed = move_target->GetComputedValues();
const Position position = computed.position();
SetDefiniteMargins(move_target, computed);
auto ResolveValueOrInvoke = [](const LengthPercentageAuto& value, float containing_block, Position position, auto&& fallback_func) {
if (value.type != LengthPercentageAuto::Auto)
return ResolveValue(value, containing_block);
if (position == Position::Relative)
return 0.0f;
return fallback_func();
};
// The following is derived at by solving the expressions in 'Element::UpdateOffset' for the computed top/left values.
move_original_position_top_left.x = ResolveValueOrInvoke(computed.left(), containing_block.x, position, [&] {
return move_target->GetOffsetLeft() -
(box.GetEdge(BoxArea::Margin, BoxEdge::Left) + parent_box.GetEdge(BoxArea::Border, BoxEdge::Left));
});
move_original_position_top_left.y = ResolveValueOrInvoke(computed.top(), containing_block.y, position, [&] {
return move_target->GetOffsetTop() -
(box.GetEdge(BoxArea::Margin, BoxEdge::Top) + parent_box.GetEdge(BoxArea::Border, BoxEdge::Top));
});
// For the bottom-right positions, we don't need to find the 'auto'-invoked expressions like above,
// since the following value is only used when bottom-right is non-auto.
move_original_position_bottom_right.x = ResolveValue(computed.right(), containing_block.x);
move_original_position_bottom_right.y = ResolveValue(computed.bottom(), containing_block.y);
move_bottom_right.x = (computed.right().type != Right::Auto);
move_bottom_right.y = (computed.bottom().type != Bottom::Auto);
move_top_left.x = (!move_bottom_right.x || computed.left().type != Left::Auto);
move_top_left.y = (!move_bottom_right.y || computed.top().type != Top::Auto);
}
if (size_target && context)
{
using namespace Style;
const Box& box = size_target->GetBox();
const auto& computed = size_target->GetComputedValues();
const Vector2f containing_block = size_target->GetContainingBlock();
SetDefiniteMargins(size_target, computed);
size_original_size = box.GetSize(computed.box_sizing() == BoxSizing::BorderBox ? BoxArea::Border : BoxArea::Content);
size_original_position_bottom_right.x = ResolveValue(computed.right(), containing_block.x);
size_original_position_bottom_right.y = ResolveValue(computed.bottom(), containing_block.y);
size_bottom_right.x = (computed.right().type != Right::Auto);
size_bottom_right.y = (computed.bottom().type != Bottom::Auto);
size_width_height.x =
(computed.left().type == Left::Auto || computed.right().type == Right::Auto || computed.width().type != Width::Auto);
size_width_height.y =
(computed.top().type == Top::Auto || computed.bottom().type == Bottom::Auto || computed.height().type != Height::Auto);
}
}
else if (event == EventId::Drag)
{
const Vector2f delta = event.GetUnprojectedMouseScreenPos() - drag_start;
if (move_target)
{
const Vector2f new_position_top_left = (move_original_position_top_left + delta).Round();
const Vector2f new_position_bottom_right = (move_original_position_bottom_right - delta).Round();
if (move_top_left.x)
move_target->SetProperty(PropertyId::Left, Property(new_position_top_left.x, Unit::PX));
if (move_top_left.y)
move_target->SetProperty(PropertyId::Top, Property(new_position_top_left.y, Unit::PX));
if (move_bottom_right.x)
move_target->SetProperty(PropertyId::Right, Property(new_position_bottom_right.x, Unit::PX));
if (move_bottom_right.y)
move_target->SetProperty(PropertyId::Bottom, Property(new_position_bottom_right.y, Unit::PX));
}
if (size_target)
{
const Vector2f new_size = Math::Max((size_original_size + delta).Round(), Vector2f(0.f));
const Vector2f new_position_bottom_right = (size_original_position_bottom_right - delta).Round();
if (size_width_height.x)
size_target->SetProperty(PropertyId::Width, Property(new_size.x, Unit::PX));
if (size_width_height.y)
size_target->SetProperty(PropertyId::Height, Property(new_size.y, Unit::PX));
if (size_bottom_right.x)
size_target->SetProperty(PropertyId::Right, Property(new_position_bottom_right.x, Unit::PX));
if (size_bottom_right.y)
size_target->SetProperty(PropertyId::Bottom, Property(new_position_bottom_right.y, Unit::PX));
}
Dictionary parameters;
parameters["handle_x"] = delta.x;
parameters["handle_y"] = delta.y;
DispatchEvent(EventId::Handledrag, parameters);
}
}
}
} // namespace Rml