godot/editor/editor_zoom_widget.cpp

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/*  editor_zoom_widget.cpp                                               */
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#include "editor_zoom_widget.h"

#include "core/os/keyboard.h"
#include "editor/editor_scale.h"
#include "editor/editor_settings.h"

void EditorZoomWidget::_update_zoom_label() {
	String zoom_text;
	// The zoom level displayed is relative to the editor scale
	// (like in most image editors). Its lower bound is clamped to 1 as some people
	// lower the editor scale to increase the available real estate,
	// even if their display doesn't have a particularly low DPI.
	if (zoom >= 10) {
		// Don't show a decimal when the zoom level is higher than 1000 %.
		zoom_text = TS->format_number(rtos(Math::round((zoom / MAX(1, EDSCALE)) * 100))) + " " + TS->percent_sign();
	} else {
		zoom_text = TS->format_number(rtos(Math::snapped((zoom / MAX(1, EDSCALE)) * 100, 0.1))) + " " + TS->percent_sign();
	}

	zoom_reset->set_text(zoom_text);
}

void EditorZoomWidget::_button_zoom_minus() {
	set_zoom_by_increments(-6);
	emit_signal("zoom_changed", zoom);
}

void EditorZoomWidget::_button_zoom_reset() {
	set_zoom(1.0);
	emit_signal("zoom_changed", zoom);
}

void EditorZoomWidget::_button_zoom_plus() {
	set_zoom_by_increments(6);
	emit_signal("zoom_changed", zoom);
}

float EditorZoomWidget::get_zoom() {
	return zoom;
}

void EditorZoomWidget::set_zoom(float p_zoom) {
	if (p_zoom > 0 && p_zoom != zoom) {
		zoom = p_zoom;
		_update_zoom_label();
	}
}

void EditorZoomWidget::set_zoom_by_increments(int p_increment_count) {
	// Base increment factor defined as the twelveth root of two.
	// This allow a smooth geometric evolution of the zoom, with the advantage of
	// visiting all integer power of two scale factors.
	// note: this is analogous to the 'semitones' interval in the music world
	// In order to avoid numerical imprecisions, we compute and edit a zoom index
	// with the following relation: zoom = 2 ^ (index / 12)

	if (zoom < CMP_EPSILON || p_increment_count == 0) {
		return;
	}

	// Remove Editor scale from the index computation
	float zoom_noscale = zoom / MAX(1, EDSCALE);

	// zoom = 2**(index/12) => log2(zoom) = index/12
	float closest_zoom_index = Math::round(Math::log(zoom_noscale) * 12.f / Math::log(2.f));

	float new_zoom_index = closest_zoom_index + p_increment_count;
	float new_zoom = Math::pow(2.f, new_zoom_index / 12.f);

	// Restore Editor scale transformation
	new_zoom *= MAX(1, EDSCALE);

	set_zoom(new_zoom);
}

void EditorZoomWidget::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE:
		case NOTIFICATION_THEME_CHANGED:
			zoom_minus->set_icon(get_theme_icon("ZoomLess", "EditorIcons"));
			zoom_plus->set_icon(get_theme_icon("ZoomMore", "EditorIcons"));
			break;
		default:
			break;
	}
}

void EditorZoomWidget::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_zoom", "zoom"), &EditorZoomWidget::set_zoom);
	ClassDB::bind_method(D_METHOD("get_zoom"), &EditorZoomWidget::get_zoom);
	ClassDB::bind_method(D_METHOD("set_zoom_by_increments", "increment"), &EditorZoomWidget::set_zoom_by_increments);

	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "zoom"), "set_zoom", "get_zoom");

	ADD_SIGNAL(MethodInfo("zoom_changed", PropertyInfo(Variant::FLOAT, "zoom")));
}

EditorZoomWidget::EditorZoomWidget() {
	// Zoom buttons
	zoom_minus = memnew(Button);
	zoom_minus->set_flat(true);
	add_child(zoom_minus);
	zoom_minus->connect("pressed", callable_mp(this, &EditorZoomWidget::_button_zoom_minus));
	zoom_minus->set_shortcut(ED_SHORTCUT("canvas_item_editor/zoom_minus", TTR("Zoom Out"), KEY_MASK_CMD | KEY_MINUS));
	zoom_minus->set_shortcut_context(this);
	zoom_minus->set_focus_mode(FOCUS_NONE);

	zoom_reset = memnew(Button);
	zoom_reset->set_flat(true);
	add_child(zoom_reset);
	zoom_reset->add_theme_constant_override("outline_size", 1);
	zoom_reset->add_theme_color_override("font_outline_color", Color(0, 0, 0));
	zoom_reset->add_theme_color_override("font_color", Color(1, 1, 1));
	zoom_reset->connect("pressed", callable_mp(this, &EditorZoomWidget::_button_zoom_reset));
	zoom_reset->set_shortcut(ED_SHORTCUT("canvas_item_editor/zoom_reset", TTR("Zoom Reset"), KEY_MASK_CMD | KEY_0));
	zoom_reset->set_shortcut_context(this);
	zoom_reset->set_focus_mode(FOCUS_NONE);
	zoom_reset->set_text_align(Button::TextAlign::ALIGN_CENTER);
	// Prevent the button's size from changing when the text size changes
	zoom_reset->set_custom_minimum_size(Size2(75 * EDSCALE, 0));

	zoom_plus = memnew(Button);
	zoom_plus->set_flat(true);
	add_child(zoom_plus);
	zoom_plus->connect("pressed", callable_mp(this, &EditorZoomWidget::_button_zoom_plus));
	zoom_plus->set_shortcut(ED_SHORTCUT("canvas_item_editor/zoom_plus", TTR("Zoom In"), KEY_MASK_CMD | KEY_EQUAL)); // Usually direct access key for PLUS
	zoom_plus->set_shortcut_context(this);
	zoom_plus->set_focus_mode(FOCUS_NONE);

	_update_zoom_label();

	add_theme_constant_override("separation", Math::round(-8 * EDSCALE));
}