Add scroll hints to ScrollContainer and Tree

Author: YeldhamDev

doc/classes/ScrollContainer.xml

@@ -52,6 +52,10 @@
 		<member name="scroll_deadzone" type="int" setter="set_deadzone" getter="get_deadzone" default="0">
 			Deadzone for touch scrolling. Lower deadzone makes the scrolling more sensitive.
 		</member>
+		<member name="scroll_hint_mode" type="int" setter="set_scroll_hint_mode" getter="get_scroll_hint_mode" enum="ScrollContainer.ScrollHintMode" default="0">
+			The way which scroll hints (indicators that show that the content can still be scrolled in a certain direction) will be shown.
+			[b]Note:[/b] Hints won't be shown if the content can be scroll both vertically and horizontally.
+		</member>
 		<member name="scroll_horizontal" type="int" setter="set_h_scroll" getter="get_h_scroll" default="0">
 			The current horizontal scroll value.
 			[b]Note:[/b] If you are setting this value in the [method Node._ready] function or earlier, it needs to be wrapped with [method Object.set_deferred], since scroll bar's [member Range.max_value] is not initialized yet.
@@ -74,6 +78,9 @@
 		<member name="scroll_vertical_custom_step" type="float" setter="set_vertical_custom_step" getter="get_vertical_custom_step" default="-1.0">
 			Overrides the [member ScrollBar.custom_step] used when clicking the internal scroll bar's vertical increment and decrement buttons or when using arrow keys when the [ScrollBar] is focused.
 		</member>
+		<member name="tile_scroll_hint" type="bool" setter="set_tile_scroll_hint" getter="is_scroll_hint_tiled" default="false">
+			If [code]true[/code], the scroll hint texture will be tiled instead of stretched. See [member scroll_hint_mode].
+		</member>
 		<member name="vertical_scroll_mode" type="int" setter="set_vertical_scroll_mode" getter="get_vertical_scroll_mode" enum="ScrollContainer.ScrollMode" default="1">
 			Controls whether vertical scrollbar can be used and when it should be visible.
 		</member>
@@ -108,6 +115,18 @@
 		<constant name="SCROLL_MODE_RESERVE" value="4" enum="ScrollMode">
 			Combines [constant SCROLL_MODE_AUTO] and [constant SCROLL_MODE_SHOW_ALWAYS]. The scrollbar is only visible if necessary, but the content size is adjusted as if it was always visible. It's useful for ensuring that content size stays the same regardless if the scrollbar is visible.
 		</constant>
+		<constant name="SCROLL_HINT_MODE_DISABLED" value="0" enum="ScrollHintMode">
+			Scroll hints will never be shown.
+		</constant>
+		<constant name="SCROLL_HINT_MODE_ALL" value="1" enum="ScrollHintMode">
+			Scroll hints will be shown in the top and bottom (if horizontal), or left and right (if vertical).
+		</constant>
+		<constant name="SCROLL_HINT_MODE_TOP_AND_LEFT" value="2" enum="ScrollHintMode">
+			Scroll hints will be shown in the top (if horizontal), or the left (if vertical).
+		</constant>
+		<constant name="SCROLL_HINT_MODE_BOTTOM_AND_RIGHT" value="3" enum="ScrollHintMode">
+			Scroll hints will be shown in the bottom (if horizontal), or the right (if vertical).
+		</constant>
 	</constants>
 	<theme_items>
 		<theme_item name="scrollbar_h_separation" data_type="constant" type="int" default="0">
@@ -116,6 +135,12 @@
 		<theme_item name="scrollbar_v_separation" data_type="constant" type="int" default="0">
 			The space between the ScrollContainer's horizontal scroll bar and its content, in pixels. No space will be added when the content's minimum size is larger than the ScrollContainer's size.
 		</theme_item>
+		<theme_item name="scroll_hint_horizontal" data_type="icon" type="Texture2D">
+			The indicator that will be shown when the content can still be scrolled horizontally. See [member scroll_hint_mode].
+		</theme_item>
+		<theme_item name="scroll_hint_vertical" data_type="icon" type="Texture2D">
+			The indicator that will be shown when the content can still be scrolled vertically. See [member scroll_hint_mode].
+		</theme_item>
 		<theme_item name="focus" data_type="style" type="StyleBox">
 			The focus border [StyleBox] of the [ScrollContainer]. Only used if [member draw_focus_border] is [code]true[/code].
 		</theme_item>

doc/classes/Tree.xml

@@ -383,6 +383,9 @@
 		<member name="hide_root" type="bool" setter="set_hide_root" getter="is_root_hidden" default="false">
 			If [code]true[/code], the tree's root is hidden.
 		</member>
+		<member name="scroll_hint_mode" type="int" setter="set_scroll_hint_mode" getter="get_scroll_hint_mode" enum="Tree.ScrollHintMode" default="0">
+			The way which scroll hints (indicators that show that the content can still be scrolled in a certain direction) will be shown.
+		</member>
 		<member name="scroll_horizontal_enabled" type="bool" setter="set_h_scroll_enabled" getter="is_h_scroll_enabled" default="true">
 			If [code]true[/code], enables horizontal scrolling.
 		</member>
@@ -392,6 +395,9 @@
 		<member name="select_mode" type="int" setter="set_select_mode" getter="get_select_mode" enum="Tree.SelectMode" default="0">
 			Allows single or multiple selection. See the [enum SelectMode] constants.
 		</member>
+		<member name="tile_scroll_hint" type="bool" setter="set_tile_scroll_hint" getter="is_scroll_hint_tiled" default="false">
+			If [code]true[/code], the scroll hint texture will be tiled instead of stretched. See [member scroll_hint_mode].
+		</member>
 	</members>
 	<signals>
 		<signal name="button_clicked">
@@ -514,6 +520,18 @@
 			Enables "above item" and "below item" drop sections. The "above item" drop section covers the top half of the item, and the "below item" drop section covers the bottom half.
 			When combined with [constant DROP_MODE_ON_ITEM], these drop sections halves the height and stays on top / bottom accordingly.
 		</constant>
+		<constant name="SCROLL_HINT_MODE_DISABLED" value="0" enum="ScrollHintMode">
+			Scroll hints will never be shown.
+		</constant>
+		<constant name="SCROLL_HINT_MODE_BOTH" value="1" enum="ScrollHintMode">
+			Scroll hints will be shown in the top and bottom.
+		</constant>
+		<constant name="SCROLL_HINT_MODE_TOP" value="2" enum="ScrollHintMode">
+			Only the top scroll hint will be shown.
+		</constant>
+		<constant name="SCROLL_HINT_MODE_BOTTOM" value="3" enum="ScrollHintMode">
+			Only the bottom scroll hint will be shown.
+		</constant>
 	</constants>
 	<theme_items>
 		<theme_item name="children_hl_line_color" data_type="color" type="Color" default="Color(0.27, 0.27, 0.27, 1)">
@@ -667,6 +685,9 @@
 		<theme_item name="indeterminate_disabled" data_type="icon" type="Texture2D">
 			The check icon to display when the [constant TreeItem.CELL_MODE_CHECK] mode cell is indeterminate and non-editable (see [method TreeItem.set_editable]).
 		</theme_item>
+		<theme_item name="scroll_hint" data_type="icon" type="Texture2D">
+			The indicator that will be shown when the content can still be scrolled. See [member scroll_hint_mode].
+		</theme_item>
 		<theme_item name="select_arrow" data_type="icon" type="Texture2D">
 			The arrow icon to display for the [constant TreeItem.CELL_MODE_RANGE] mode cell.
 		</theme_item>

editor/themes/theme_classic.cpp

@@ -35,6 +35,7 @@
 #include "editor/themes/editor_scale.h"
 #include "editor/themes/editor_theme_manager.h"
 #include "scene/gui/graph_edit.h"
+#include "scene/resources/compressed_texture.h"
 #include "scene/resources/dpi_texture.h"
 #include "scene/resources/image_texture.h"
 #include "scene/resources/style_box_flat.h"
@@ -1551,6 +1552,13 @@ void ThemeClassic::populate_editor_styles(const Ref<EditorTheme> &p_theme, Edito
 		Ref<StyleBoxFlat> style_widget_scroll_container = p_config.button_style_focus->duplicate();
 		p_theme->set_stylebox("focus", "ScrollContainer", style_widget_scroll_container);
 
+		// Hide scroll hints.
+		Ref<CompressedTexture2D> empty_texture;
+		empty_texture.instantiate();
+		p_theme->set_icon("scroll_hint_vertical", "ScrollContainer", empty_texture);
+		p_theme->set_icon("scroll_hint_horizontal", "ScrollContainer", empty_texture);
+		p_theme->set_icon("scroll_hint", "Tree", empty_texture);
+
 		// This stylebox is used in 3d and 2d viewports (no borders).
 		Ref<StyleBoxFlat> style_content_panel_vp = p_config.content_panel_style->duplicate();
 		style_content_panel_vp->set_content_margin_individual(p_config.border_width * 2, p_config.base_margin * EDSCALE, p_config.border_width * 2, p_config.border_width * 2);

scene/gui/scroll_container.cpp

@@ -32,6 +32,7 @@
 
 #include "core/config/project_settings.h"
 #include "scene/gui/panel_container.h"
+#include "scene/gui/texture_rect.h"
 #include "scene/main/window.h"
 #include "scene/theme/theme_db.h"
 
@@ -343,6 +344,7 @@ void ScrollContainer::ensure_control_visible(Control *p_control) {
 
 void ScrollContainer::_reposition_children() {
 	update_scrollbars();
+	update_scroll_hints();
 
 	Rect2 margins = _get_margins();
 	Size2 size = get_size();
@@ -362,10 +364,7 @@ void ScrollContainer::_reposition_children() {
 
 	for (int i = 0; i < get_child_count(); i++) {
 		Control *c = as_sortable_control(get_child(i));
-		if (!c) {
-			continue;
-		}
-		if (c == h_scroll || c == v_scroll || c == focus_panel) {
+		if (!c || c->is_internal()) {
 			continue;
 		}
 		Size2 minsize = c->get_combined_minimum_size();
@@ -445,7 +444,10 @@ void ScrollContainer::_notification(int p_what) {
 			DisplayServer::get_singleton()->accessibility_update_add_action(ae, DisplayServer::AccessibilityAction::ACTION_SET_SCROLL_OFFSET, callable_mp(this, &ScrollContainer::_accessibility_action_scroll_set));
 		} break;
 
-		case NOTIFICATION_THEME_CHANGED:
+		case NOTIFICATION_THEME_CHANGED: {
+			update_scroll_hints();
+			[[fallthrough]];
+		}
 		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED:
 		case NOTIFICATION_TRANSLATION_CHANGED: {
 			_updating_scrollbars = true;
@@ -602,6 +604,42 @@ void ScrollContainer::update_scrollbars() {
 	callable_mp(this, &ScrollContainer::_update_scrollbar_position).call_deferred();
 }
 
+void ScrollContainer::update_scroll_hints() {
+	Size2 size = get_size();
+	Rect2 margins = _get_margins();
+	Size2 scroll_size = size - margins.position + margins.size;
+
+	float v_scroll_value = v_scroll->get_value();
+	bool v_scroll_below_max = v_scroll_value < (largest_child_min_size.height - scroll_size.height - 1);
+	bool show_vertical_hints = v_scroll_value > 1 || v_scroll_below_max;
+
+	float h_scroll_value = h_scroll->get_value();
+	bool h_scroll_below_max = h_scroll_value < (largest_child_min_size.width - scroll_size.width - 1);
+	bool show_horizontal_hints = h_scroll_value > 1 || h_scroll_below_max;
+
+	if (show_vertical_hints) {
+		scroll_hint_top_left->set_texture(theme_cache.scroll_hint_vertical);
+		scroll_hint_top_left->set_offsets_preset(PRESET_TOP_WIDE, LayoutPresetMode::PRESET_MODE_MINSIZE);
+		scroll_hint_top_left->set_visible(!show_horizontal_hints && (scroll_hint_mode == SCROLL_HINT_MODE_ALL || scroll_hint_mode == SCROLL_HINT_MODE_TOP_AND_LEFT) && v_scroll_value > 1);
+
+		scroll_hint_bottom_right->set_flip_h(false);
+		scroll_hint_bottom_right->set_flip_v(true);
+		scroll_hint_bottom_right->set_texture(theme_cache.scroll_hint_vertical);
+		scroll_hint_bottom_right->set_offsets_preset(PRESET_BOTTOM_WIDE, LayoutPresetMode::PRESET_MODE_MINSIZE);
+		scroll_hint_bottom_right->set_visible(!show_horizontal_hints && (scroll_hint_mode == SCROLL_HINT_MODE_ALL || scroll_hint_mode == SCROLL_HINT_MODE_BOTTOM_AND_RIGHT) && v_scroll_below_max);
+	} else {
+		scroll_hint_top_left->set_texture(theme_cache.scroll_hint_horizontal);
+		scroll_hint_top_left->set_offsets_preset(PRESET_LEFT_WIDE, LayoutPresetMode::PRESET_MODE_MINSIZE);
+		scroll_hint_top_left->set_visible(!show_vertical_hints && (scroll_hint_mode == SCROLL_HINT_MODE_ALL || scroll_hint_mode == SCROLL_HINT_MODE_TOP_AND_LEFT) && h_scroll_value > 1);
+
+		scroll_hint_bottom_right->set_flip_h(true);
+		scroll_hint_bottom_right->set_flip_v(false);
+		scroll_hint_bottom_right->set_texture(theme_cache.scroll_hint_horizontal);
+		scroll_hint_bottom_right->set_offsets_preset(PRESET_RIGHT_WIDE, LayoutPresetMode::PRESET_MODE_MINSIZE);
+		scroll_hint_bottom_right->set_visible(!show_vertical_hints && (scroll_hint_mode == SCROLL_HINT_MODE_ALL || scroll_hint_mode == SCROLL_HINT_MODE_BOTTOM_AND_RIGHT) && h_scroll_below_max);
+	}
+}
+
 void ScrollContainer::_scroll_moved(float) {
 	queue_sort();
 }
@@ -676,6 +714,32 @@ void ScrollContainer::set_deadzone(int p_deadzone) {
 	deadzone = p_deadzone;
 }
 
+void ScrollContainer::set_scroll_hint_mode(ScrollHintMode p_mode) {
+	ScrollHintMode prev_mode = scroll_hint_mode;
+	scroll_hint_mode = p_mode;
+
+	if (scroll_hint_mode != prev_mode) {
+		queue_redraw();
+	}
+}
+
+ScrollContainer::ScrollHintMode ScrollContainer::get_scroll_hint_mode() const {
+	return scroll_hint_mode;
+}
+
+void ScrollContainer::set_tile_scroll_hint(bool p_enable) {
+	bool prev_tile = tile_scroll_hint;
+	tile_scroll_hint = p_enable;
+
+	if (tile_scroll_hint != prev_tile) {
+		queue_redraw();
+	}
+}
+
+bool ScrollContainer::is_scroll_hint_tiled() {
+	return tile_scroll_hint;
+}
+
 bool ScrollContainer::is_following_focus() const {
 	return follow_focus;
 }
@@ -742,6 +806,12 @@ void ScrollContainer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_deadzone", "deadzone"), &ScrollContainer::set_deadzone);
 	ClassDB::bind_method(D_METHOD("get_deadzone"), &ScrollContainer::get_deadzone);
 
+	ClassDB::bind_method(D_METHOD("set_scroll_hint_mode", "scroll_hint_mode"), &ScrollContainer::set_scroll_hint_mode);
+	ClassDB::bind_method(D_METHOD("get_scroll_hint_mode"), &ScrollContainer::get_scroll_hint_mode);
+
+	ClassDB::bind_method(D_METHOD("set_tile_scroll_hint", "tile_scroll_hint"), &ScrollContainer::set_tile_scroll_hint);
+	ClassDB::bind_method(D_METHOD("is_scroll_hint_tiled"), &ScrollContainer::is_scroll_hint_tiled);
+
 	ClassDB::bind_method(D_METHOD("set_follow_focus", "enabled"), &ScrollContainer::set_follow_focus);
 	ClassDB::bind_method(D_METHOD("is_following_focus"), &ScrollContainer::is_following_focus);
 
@@ -758,7 +828,7 @@ void ScrollContainer::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "follow_focus"), "set_follow_focus", "is_following_focus");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "draw_focus_border"), "set_draw_focus_border", "get_draw_focus_border");
 
-	ADD_GROUP("Scroll", "scroll_");
+	ADD_GROUP("Scrollbar", "");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "scroll_horizontal", PROPERTY_HINT_NONE, "suffix:px"), "set_h_scroll", "get_h_scroll");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "scroll_vertical", PROPERTY_HINT_NONE, "suffix:px"), "set_v_scroll", "get_v_scroll");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "scroll_horizontal_custom_step", PROPERTY_HINT_RANGE, "-1,4096,suffix:px"), "set_horizontal_custom_step", "get_horizontal_custom_step");
@@ -767,18 +837,30 @@ void ScrollContainer::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "vertical_scroll_mode", PROPERTY_HINT_ENUM, "Disabled,Auto,Always Show,Never Show,Reserve"), "set_vertical_scroll_mode", "get_vertical_scroll_mode");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "scroll_deadzone"), "set_deadzone", "get_deadzone");
 
+	ADD_GROUP("Scroll Hint", "");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "scroll_hint_mode", PROPERTY_HINT_ENUM, "Disabled,All,Top and Left,Bottom and Right"), "set_scroll_hint_mode", "get_scroll_hint_mode");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "tile_scroll_hint"), "set_tile_scroll_hint", "is_scroll_hint_tiled");
+
 	BIND_ENUM_CONSTANT(SCROLL_MODE_DISABLED);
 	BIND_ENUM_CONSTANT(SCROLL_MODE_AUTO);
 	BIND_ENUM_CONSTANT(SCROLL_MODE_SHOW_ALWAYS);
 	BIND_ENUM_CONSTANT(SCROLL_MODE_SHOW_NEVER);
 	BIND_ENUM_CONSTANT(SCROLL_MODE_RESERVE);
 
+	BIND_ENUM_CONSTANT(SCROLL_HINT_MODE_DISABLED);
+	BIND_ENUM_CONSTANT(SCROLL_HINT_MODE_ALL);
+	BIND_ENUM_CONSTANT(SCROLL_HINT_MODE_TOP_AND_LEFT);
+	BIND_ENUM_CONSTANT(SCROLL_HINT_MODE_BOTTOM_AND_RIGHT);
+
 	BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, ScrollContainer, scrollbar_h_separation);
 	BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, ScrollContainer, scrollbar_v_separation);
 
 	BIND_THEME_ITEM_CUSTOM(Theme::DATA_TYPE_STYLEBOX, ScrollContainer, panel_style, "panel");
 	BIND_THEME_ITEM_CUSTOM(Theme::DATA_TYPE_STYLEBOX, ScrollContainer, focus_style, "focus");
 
+	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, ScrollContainer, scroll_hint_vertical);
+	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, ScrollContainer, scroll_hint_horizontal);
+
 	GLOBAL_DEF("gui/common/default_scroll_deadzone", 0);
 }
 
@@ -802,6 +884,16 @@ bool ScrollContainer::child_has_focus() {
 }
 
 ScrollContainer::ScrollContainer() {
+	scroll_hint_top_left = memnew(TextureRect);
+	scroll_hint_top_left->set_mouse_filter(MOUSE_FILTER_IGNORE);
+	scroll_hint_top_left->hide();
+	add_child(scroll_hint_top_left, false, INTERNAL_MODE_BACK);
+
+	scroll_hint_bottom_right = memnew(TextureRect);
+	scroll_hint_bottom_right->set_mouse_filter(MOUSE_FILTER_IGNORE);
+	scroll_hint_bottom_right->hide();
+	add_child(scroll_hint_bottom_right, false, INTERNAL_MODE_BACK);
+
 	h_scroll = memnew(HScrollBar);
 	h_scroll->set_name("_h_scroll");
 	add_child(h_scroll, false, INTERNAL_MODE_BACK);

scene/gui/scroll_container.h

@@ -35,6 +35,7 @@
 #include "scroll_bar.h"
 
 class PanelContainer;
+class TextureRect;
 
 class ScrollContainer : public Container {
 	GDCLASS(ScrollContainer, Container);
@@ -48,6 +49,13 @@ class ScrollContainer : public Container {
 		SCROLL_MODE_RESERVE,
 	};
 
+	enum ScrollHintMode {
+		SCROLL_HINT_MODE_DISABLED,
+		SCROLL_HINT_MODE_ALL,
+		SCROLL_HINT_MODE_TOP_AND_LEFT,
+		SCROLL_HINT_MODE_BOTTOM_AND_RIGHT,
+	};
+
 private:
 	HScrollBar *h_scroll = nullptr;
 	VScrollBar *v_scroll = nullptr;
@@ -67,18 +75,29 @@ class ScrollContainer : public Container {
 	bool beyond_deadzone = false;
 	bool scroll_on_drag_hover = false;
 
+	TextureRect *scroll_hint_top_left = nullptr;
+	TextureRect *scroll_hint_bottom_right = nullptr;
+
 	ScrollMode horizontal_scroll_mode = SCROLL_MODE_AUTO;
 	ScrollMode vertical_scroll_mode = SCROLL_MODE_AUTO;
 
+	void update_scroll_hints();
+
 	int deadzone = 0;
 	bool follow_focus = false;
 	int scroll_border = 20;
 	int scroll_speed = 12;
 
+	ScrollHintMode scroll_hint_mode = SCROLL_HINT_MODE_DISABLED;
+	bool tile_scroll_hint = false;
+
 	struct ThemeCache {
 		Ref<StyleBox> panel_style;
 		Ref<StyleBox> focus_style;
 
+		Ref<Texture2D> scroll_hint_vertical;
+		Ref<Texture2D> scroll_hint_horizontal;
+
 		int scrollbar_h_separation = 0;
 		int scrollbar_v_separation = 0;
 	} theme_cache;
@@ -134,8 +153,14 @@ class ScrollContainer : public Container {
 	void set_vertical_scroll_mode(ScrollMode p_mode);
 	ScrollMode get_vertical_scroll_mode() const;
 
-	int get_deadzone() const;
 	void set_deadzone(int p_deadzone);
+	int get_deadzone() const;
+
+	void set_scroll_hint_mode(ScrollHintMode p_mode);
+	ScrollHintMode get_scroll_hint_mode() const;
+
+	void set_tile_scroll_hint(bool p_enable);
+	bool is_scroll_hint_tiled();
 
 	bool is_following_focus() const;
 	void set_follow_focus(bool p_follow);
@@ -155,3 +180,4 @@ class ScrollContainer : public Container {
 };
 
 VARIANT_ENUM_CAST(ScrollContainer::ScrollMode);
+VARIANT_ENUM_CAST(ScrollContainer::ScrollHintMode);