/**************************************************************************/
/*  editor_bottom_panel.cpp                                               */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* 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     */
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/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
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#include "editor_bottom_panel.h"

#include "editor/debugger/editor_debugger_node.h"
#include "editor/editor_command_palette.h"
#include "editor/editor_node.h"
#include "editor/editor_string_names.h"
#include "editor/gui/editor_toaster.h"
#include "editor/gui/editor_version_button.h"
#include "editor/themes/editor_scale.h"
#include "scene/gui/box_container.h"
#include "scene/gui/button.h"
#include "scene/gui/scroll_container.h"
#include "scene/gui/split_container.h"

void EditorBottomPanel::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_THEME_CHANGED: {
			pin_button->set_button_icon(get_editor_theme_icon(SNAME("Pin")));
			expand_button->set_button_icon(get_editor_theme_icon(SNAME("ExpandBottomDock")));
			left_button->set_button_icon(get_editor_theme_icon(SNAME("Back")));
			right_button->set_button_icon(get_editor_theme_icon(SNAME("Forward")));
		} break;

		case NOTIFICATION_TRANSLATION_CHANGED:
		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED: {
			if (is_layout_rtl()) {
				bottom_hbox->move_child(left_button, button_scroll->get_index() + 1);
				bottom_hbox->move_child(right_button, 0);
			} else {
				bottom_hbox->move_child(right_button, button_scroll->get_index() + 1);
				bottom_hbox->move_child(left_button, 0);
			}
		} break;
	}
}

void EditorBottomPanel::_switch_by_control(bool p_visible, Control *p_control, bool p_ignore_lock) {
	for (int i = 0; i < items.size(); i++) {
		if (items[i].control == p_control) {
			_switch_to_item(p_visible, i, p_ignore_lock);
			return;
		}
	}
}

void EditorBottomPanel::_scroll(bool p_right) {
	HScrollBar *h_scroll = button_scroll->get_h_scroll_bar();
	if (Input::get_singleton()->is_key_pressed(Key::CTRL)) {
		h_scroll->set_value(p_right ? h_scroll->get_max() : 0);
	} else if (Input::get_singleton()->is_key_pressed(Key::SHIFT)) {
		h_scroll->set_value(h_scroll->get_value() + h_scroll->get_page() * (p_right ? 1 : -1));
	} else {
		h_scroll->set_value(h_scroll->get_value() + (h_scroll->get_page() * 0.5) * (p_right ? 1 : -1));
	}
}

void EditorBottomPanel::_update_scroll_buttons() {
	bool show_arrows = button_hbox->get_size().width > button_scroll->get_size().width;
	left_button->set_visible(show_arrows);
	right_button->set_visible(show_arrows);

	if (show_arrows) {
		_update_disabled_buttons();
	}
}

void EditorBottomPanel::_update_disabled_buttons() {
	HScrollBar *h_scroll = button_scroll->get_h_scroll_bar();
	left_button->set_disabled(h_scroll->get_value() == 0);
	right_button->set_disabled(h_scroll->get_value() + h_scroll->get_page() == h_scroll->get_max());
}

void EditorBottomPanel::_switch_to_item(bool p_visible, int p_idx, bool p_ignore_lock) {
	ERR_FAIL_INDEX(p_idx, items.size());

	if (items[p_idx].control->is_visible() == p_visible) {
		return;
	}

	SplitContainer *center_split = Object::cast_to<SplitContainer>(get_parent());
	ERR_FAIL_NULL(center_split);

	if (p_visible) {
		if (!p_ignore_lock && lock_panel_switching && pin_button->is_visible()) {
			return;
		}

		for (int i = 0; i < items.size(); i++) {
			items[i].button->set_pressed_no_signal(i == p_idx);
			items[i].control->set_visible(i == p_idx);
		}
		if (EditorDebuggerNode::get_singleton() == items[p_idx].control) {
			// This is the debug panel which uses tabs, so the top section should be smaller.
			add_theme_style_override(SceneStringName(panel), get_theme_stylebox(SNAME("BottomPanelDebuggerOverride"), EditorStringName(EditorStyles)));
		} else {
			add_theme_style_override(SceneStringName(panel), get_theme_stylebox(SNAME("BottomPanel"), EditorStringName(EditorStyles)));
		}

		center_split->set_dragger_visibility(SplitContainer::DRAGGER_VISIBLE);
		center_split->set_collapsed(false);
		pin_button->show();

		expand_button->show();
		if (expand_button->is_pressed()) {
			EditorNode::get_top_split()->hide();
		}
		callable_mp(button_scroll, &ScrollContainer::ensure_control_visible).call_deferred(items[p_idx].button);
	} else {
		add_theme_style_override(SceneStringName(panel), get_theme_stylebox(SNAME("BottomPanel"), EditorStringName(EditorStyles)));
		items[p_idx].button->set_pressed_no_signal(false);
		items[p_idx].control->set_visible(false);
		center_split->set_dragger_visibility(SplitContainer::DRAGGER_HIDDEN);
		center_split->set_collapsed(true);
		pin_button->hide();

		expand_button->hide();
		if (expand_button->is_pressed()) {
			EditorNode::get_top_split()->show();
		}
	}

	last_opened_control = items[p_idx].control;
}

void EditorBottomPanel::_pin_button_toggled(bool p_pressed) {
	lock_panel_switching = p_pressed;
}

void EditorBottomPanel::_expand_button_toggled(bool p_pressed) {
	EditorNode::get_top_split()->set_visible(!p_pressed);
}

bool EditorBottomPanel::_button_drag_hover(const Vector2 &, const Variant &, Button *p_button, Control *p_control) {
	if (!p_button->is_pressed()) {
		_switch_by_control(true, p_control, true);
	}
	return false;
}

void EditorBottomPanel::save_layout_to_config(Ref<ConfigFile> p_config_file, const String &p_section) const {
	int selected_item_idx = -1;
	for (int i = 0; i < items.size(); i++) {
		if (items[i].button->is_pressed()) {
			selected_item_idx = i;
			break;
		}
	}
	if (selected_item_idx != -1) {
		p_config_file->set_value(p_section, "selected_bottom_panel_item", selected_item_idx);
	} else {
		p_config_file->set_value(p_section, "selected_bottom_panel_item", Variant());
	}
}

void EditorBottomPanel::load_layout_from_config(Ref<ConfigFile> p_config_file, const String &p_section) {
	bool has_active_tab = false;
	if (p_config_file->has_section_key(p_section, "selected_bottom_panel_item")) {
		int selected_item_idx = p_config_file->get_value(p_section, "selected_bottom_panel_item");
		if (selected_item_idx >= 0 && selected_item_idx < items.size()) {
			// Make sure we don't try to open contextual editors which are not enabled in the current context.
			if (items[selected_item_idx].button->is_visible()) {
				_switch_to_item(true, selected_item_idx);
				has_active_tab = true;
			}
		}
	}
	// If there is no active tab we need to collapse the panel.
	if (!has_active_tab) {
		items[0].control->show(); // _switch_to_item() can collapse only visible tabs.
		_switch_to_item(false, 0);
	}
}

Button *EditorBottomPanel::add_item(String p_text, Control *p_item, const Ref<Shortcut> &p_shortcut, bool p_at_front) {
	Button *tb = memnew(Button);
	tb->set_theme_type_variation("BottomPanelButton");
	tb->connect(SceneStringName(toggled), callable_mp(this, &EditorBottomPanel::_switch_by_control).bind(p_item, true));
	tb->set_drag_forwarding(Callable(), callable_mp(this, &EditorBottomPanel::_button_drag_hover).bind(tb, p_item), Callable());
	tb->set_text(p_text);
	tb->set_shortcut(p_shortcut);
	tb->set_toggle_mode(true);
	tb->set_focus_mode(Control::FOCUS_NONE);
	item_vbox->add_child(p_item);

	bottom_hbox->move_to_front();
	button_hbox->add_child(tb);
	if (p_at_front) {
		button_hbox->move_child(tb, 0);
	}
	p_item->set_v_size_flags(Control::SIZE_EXPAND_FILL);
	p_item->hide();

	BottomPanelItem bpi;
	bpi.button = tb;
	bpi.control = p_item;
	bpi.name = p_text;
	if (p_at_front) {
		items.insert(0, bpi);
	} else {
		items.push_back(bpi);
	}

	return tb;
}

void EditorBottomPanel::remove_item(Control *p_item) {
	bool was_visible = false;
	for (int i = 0; i < items.size(); i++) {
		if (items[i].control == p_item) {
			if (p_item->is_visible_in_tree()) {
				was_visible = true;
			}
			item_vbox->remove_child(items[i].control);
			button_hbox->remove_child(items[i].button);
			memdelete(items[i].button);
			items.remove_at(i);
			break;
		}
	}

	if (was_visible) {
		// Open the first panel to ensure that if the removed dock was visible, the bottom
		// panel will not collapse.
		_switch_to_item(true, 0, true);
	} else if (last_opened_control == p_item) {
		// When a dock is removed by plugins, it might not have been visible, and it
		// might have been the last_opened_control. We need to make sure to reset the last opened control.
		last_opened_control = items[0].control;
	}
}

void EditorBottomPanel::make_item_visible(Control *p_item, bool p_visible, bool p_ignore_lock) {
	_switch_by_control(p_visible, p_item, p_ignore_lock);
}

void EditorBottomPanel::move_item_to_end(Control *p_item) {
	for (int i = 0; i < items.size(); i++) {
		if (items[i].control == p_item) {
			items[i].button->move_to_front();
			SWAP(items.write[i], items.write[items.size() - 1]);
			break;
		}
	}
}

void EditorBottomPanel::hide_bottom_panel() {
	for (int i = 0; i < items.size(); i++) {
		if (items[i].control->is_visible()) {
			_switch_to_item(false, i);
			break;
		}
	}
}

void EditorBottomPanel::toggle_last_opened_bottom_panel() {
	// Select by control instead of index, so that the last bottom panel is opened correctly
	// if it's been reordered since.
	if (last_opened_control) {
		_switch_by_control(!last_opened_control->is_visible(), last_opened_control, true);
	} else {
		// Open the first panel in the list if no panel was opened this session.
		_switch_to_item(true, 0, true);
	}
}

void EditorBottomPanel::set_expanded(bool p_expanded) {
	expand_button->set_pressed(p_expanded);
}

EditorBottomPanel::EditorBottomPanel() {
	item_vbox = memnew(VBoxContainer);
	add_child(item_vbox);

	bottom_hbox = memnew(HBoxContainer);
	bottom_hbox->set_custom_minimum_size(Size2(0, 24 * EDSCALE)); // Adjust for the height of the "Expand Bottom Dock" icon.
	item_vbox->add_child(bottom_hbox);

	left_button = memnew(Button);
	left_button->set_tooltip_text(TTR("Scroll Left\nHold Ctrl to scroll to the begin.\nHold Shift to scroll one page."));
	left_button->set_theme_type_variation("BottomPanelButton");
	left_button->set_focus_mode(Control::FOCUS_NONE);
	left_button->connect(SceneStringName(pressed), callable_mp(this, &EditorBottomPanel::_scroll).bind(false));
	bottom_hbox->add_child(left_button);
	left_button->hide();

	button_scroll = memnew(ScrollContainer);
	button_scroll->set_h_size_flags(Control::SIZE_EXPAND_FILL);
	button_scroll->set_horizontal_scroll_mode(ScrollContainer::SCROLL_MODE_SHOW_NEVER);
	button_scroll->set_vertical_scroll_mode(ScrollContainer::SCROLL_MODE_DISABLED);
	button_scroll->get_h_scroll_bar()->connect(CoreStringName(changed), callable_mp(this, &EditorBottomPanel::_update_scroll_buttons), CONNECT_DEFERRED);
	button_scroll->get_h_scroll_bar()->connect(SceneStringName(value_changed), callable_mp(this, &EditorBottomPanel::_update_disabled_buttons).unbind(1), CONNECT_DEFERRED);
	bottom_hbox->add_child(button_scroll);

	right_button = memnew(Button);
	right_button->set_tooltip_text(TTR("Scroll Right\nHold Ctrl to scroll to the end.\nHold Shift to scroll one page."));
	right_button->set_theme_type_variation("BottomPanelButton");
	right_button->set_focus_mode(Control::FOCUS_NONE);
	right_button->connect(SceneStringName(pressed), callable_mp(this, &EditorBottomPanel::_scroll).bind(true));
	bottom_hbox->add_child(right_button);
	right_button->hide();

	callable_mp(this, &EditorBottomPanel::_update_scroll_buttons).call_deferred();

	button_hbox = memnew(HBoxContainer);
	button_hbox->set_h_size_flags(Control::SIZE_EXPAND | Control::SIZE_SHRINK_BEGIN);
	button_scroll->add_child(button_hbox);

	editor_toaster = memnew(EditorToaster);
	bottom_hbox->add_child(editor_toaster);

	EditorVersionButton *version_btn = memnew(EditorVersionButton(EditorVersionButton::FORMAT_BASIC));
	// Fade out the version label to be less prominent, but still readable.
	version_btn->set_self_modulate(Color(1, 1, 1, 0.65));
	version_btn->set_v_size_flags(Control::SIZE_SHRINK_CENTER);
	bottom_hbox->add_child(version_btn);

	// Add a dummy control node for horizontal spacing.
	Control *h_spacer = memnew(Control);
	bottom_hbox->add_child(h_spacer);

	pin_button = memnew(Button);
	bottom_hbox->add_child(pin_button);
	pin_button->hide();
	pin_button->set_theme_type_variation("FlatMenuButton");
	pin_button->set_toggle_mode(true);
	pin_button->set_tooltip_text(TTR("Pin Bottom Panel Switching"));
	pin_button->connect(SceneStringName(toggled), callable_mp(this, &EditorBottomPanel::_pin_button_toggled));

	expand_button = memnew(Button);
	bottom_hbox->add_child(expand_button);
	expand_button->hide();
	expand_button->set_theme_type_variation("FlatMenuButton");
	expand_button->set_toggle_mode(true);
	expand_button->set_shortcut(ED_SHORTCUT_AND_COMMAND("editor/bottom_panel_expand", TTRC("Expand Bottom Panel"), KeyModifierMask::SHIFT | Key::F12));
	expand_button->connect(SceneStringName(toggled), callable_mp(this, &EditorBottomPanel::_expand_button_toggled));
}