fix(tooltip): tooltip not appearing in RunMode::Lazy

include/nanogui/button.h

@@ -59,7 +59,12 @@ class NANOGUI_EXPORT Button : public Widget {
     std::string_view caption() const { return m_caption; }
 
     /// Sets the caption of this Button.
-    void set_caption(std::string_view caption) { m_caption = caption; }
+    void set_caption(std::string_view caption) {
+        if (m_caption != caption) {
+            m_caption = caption;
+            preferred_size_changed();
+        }
+    }
 
     /// Returns the background color of this Button.
     const Color &background_color() const { return m_background_color; }
@@ -74,7 +79,12 @@ class NANOGUI_EXPORT Button : public Widget {
     /// Returns the icon of this Button.  See \ref nanogui::Button::m_icon.
     int icon() const { return m_icon; }
     /// Sets the icon of this Button.  See \ref nanogui::Button::m_icon.
-    void set_icon(int icon) { m_icon = icon; }
+    void set_icon(int icon) {
+        if (m_icon != icon) {
+            m_icon = icon;
+            preferred_size_changed();
+        }
+    }
 
     /// The current flags of this Button (see \ref nanogui::Button::Flags for options).
     int flags() const { return m_flags; }
@@ -84,7 +94,12 @@ class NANOGUI_EXPORT Button : public Widget {
     /// The position of the icon for this Button.
     IconPosition icon_position() const { return m_icon_position; }
     /// Sets the position of the icon for this Button.
-    void set_icon_position(IconPosition icon_position) { m_icon_position = icon_position; }
+    void set_icon_position(IconPosition icon_position) {
+        if (m_icon_position != icon_position) {
+            m_icon_position = icon_position;
+            preferred_size_changed();
+        }
+    }
 
     /// Whether or not this Button is currently pushed.
     bool pushed() const { return m_pushed; }
@@ -109,10 +124,18 @@ class NANOGUI_EXPORT Button : public Widget {
     /// The padding of this Button.
     const Vector2i &padding() const { return m_padding; }
     /// Set the padding of this Button.
-    void set_padding(const Vector2i &padding) { m_padding = padding; }
+    void set_padding(const Vector2i &padding) {
+        if (m_padding != padding) {
+            m_padding = padding;
+            preferred_size_changed();
+        }
+    }
 
+protected:
     /// The preferred size of this Button.
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
+
+public:
     /// The callback that is called when any type of mouse button event is issued to this Button.
     virtual bool mouse_enter_event(const Vector2i &p, bool enter) override;
     virtual bool mouse_button_event(const Vector2i &p, int button, bool down, int modifiers) override;

include/nanogui/checkbox.h

@@ -52,7 +52,12 @@ class NANOGUI_EXPORT CheckBox : public Widget {
     std::string_view caption() const { return m_caption; }
 
     /// Sets the caption of this check box
-    void set_caption(std::string_view caption) { m_caption = caption; }
+    void set_caption(std::string_view caption) {
+        if (m_caption != caption) {
+            m_caption = caption;
+            preferred_size_changed();
+        }
+    }
 
     /// Return whether or not this widget is currently checked.
     const bool &checked() const { return m_checked; }
@@ -73,8 +78,11 @@ class NANOGUI_EXPORT CheckBox : public Widget {
     /// Mouse button event processing for this check box
     virtual bool mouse_button_event(const Vector2i &p, int button, bool down, int modifiers) override;
 
+protected:
     /// The preferred size of this CheckBox.
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
+
+public:
 
     /// Draws this CheckBox.
     virtual void draw(NVGcontext *ctx) override;

include/nanogui/colorwheel.h

@@ -50,8 +50,6 @@ class NANOGUI_EXPORT ColorWheel : public Widget {
     /// Sets the current Color this ColorWheel has selected.
     void set_color(const Color& color);
 
-    /// The preferred size of this ColorWheel.
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
 
     /// Draws the ColorWheel.
     virtual void draw(NVGcontext *ctx) override;
@@ -99,6 +97,9 @@ class NANOGUI_EXPORT ColorWheel : public Widget {
 
     /// The current callback to execute when the color value has changed.
     std::function<void(const Color &)> m_callback;
+
+    /// The preferred size of this ColorWheel.
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
 };
 
 NAMESPACE_END(nanogui)

include/nanogui/common.h

@@ -354,6 +354,18 @@ extern NANOGUI_EXPORT std::vector<std::pair<int, std::string>>
 extern NANOGUI_EXPORT int __nanogui_get_image(NVGcontext *ctx, std::string_view name,
                                               uint8_t *data, uint32_t size);
 
+template <typename Func> struct scope_guard {
+    scope_guard(Func &&func) : func(std::move(func)) { };
+    ~scope_guard() { func(); }
+    scope_guard(const Func &) = delete;
+    scope_guard() = delete;
+    scope_guard& operator=(const Func &) = delete;
+    scope_guard& operator=(Func&&) = delete;
+
+private:
+    Func func;
+};
+
 NAMESPACE_END(nanogui)
 
 NAMESPACE_BEGIN(drjit)

include/nanogui/graph.h

@@ -50,9 +50,9 @@ class NANOGUI_EXPORT Graph : public Widget {
     std::vector<float> &values() { return m_values; }
     void set_values(const std::vector<float> &values) { m_values = values; }
 
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
     virtual void draw(NVGcontext *ctx) override;
 protected:
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
     std::string m_caption, m_header, m_footer;
     Color m_background_color, m_fill_color, m_stroke_color, m_text_color;
     std::vector<float> m_values;

include/nanogui/imagepanel.h

@@ -28,7 +28,7 @@ class NANOGUI_EXPORT ImagePanel : public Widget {
 public:
     ImagePanel(Widget *parent);
 
-    void set_images(const Images &data) { m_images = data; }
+    void set_images(const Images &data) { m_images = data; preferred_size_changed(); }
     const Images& images() const { return m_images; }
 
     const std::function<void(int)> &callback() const { return m_callback; }
@@ -38,10 +38,10 @@ class NANOGUI_EXPORT ImagePanel : public Widget {
                                     int modifiers) override;
     virtual bool mouse_button_event(const Vector2i &p, int button, bool down,
                                     int modifiers) override;
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
     virtual void draw(NVGcontext *ctx) override;
 
 protected:
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
     Vector2i grid_size() const;
     int index_for_position(const Vector2i &p) const;
 protected:

include/nanogui/label.h

@@ -32,10 +32,20 @@ class NANOGUI_EXPORT Label : public Widget {
     /// Get the label's text caption
     std::string_view caption() const { return m_caption; }
     /// Set the label's text caption
-    void set_caption(std::string_view caption) { m_caption = caption; }
+    void set_caption(std::string_view caption) {
+        if (m_caption != caption) {
+            m_caption = caption;
+            preferred_size_changed();
+        }
+    }
 
     /// Set the currently active font (2 are available by default: 'sans' and 'sans-bold')
-    void set_font(std::string_view font) { m_font = font; }
+    void set_font(std::string_view font) {
+        if (m_font != font) {
+            m_font = font;
+            preferred_size_changed();
+        }
+    }
     /// Get the currently active font
     std::string_view font() const { return m_font; }
 
@@ -47,8 +57,11 @@ class NANOGUI_EXPORT Label : public Widget {
     /// Set the \ref Theme used to draw this widget
     virtual void set_theme(Theme *theme) override;
 
+protected:
     /// Compute the size needed to fully display the label
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
+
+public:
 
     /// Draw the label
     virtual void draw(NVGcontext *ctx) override;

include/nanogui/progressbar.h

@@ -28,9 +28,9 @@ class NANOGUI_EXPORT ProgressBar : public Widget {
     float value() { return m_value; }
     void set_value(float value) { m_value = value; }
 
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
     virtual void draw(NVGcontext* ctx) override;
 protected:
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
     float m_value;
 };
 

include/nanogui/python.h

@@ -61,8 +61,8 @@ extern "C" {
     bool keyboard_character_event(unsigned int codepoint) override {           \
         NB_OVERRIDE(keyboard_character_event, codepoint);                      \
     }                                                                          \
-    ::nanogui::Vector2i preferred_size(NVGcontext *ctx) const override {       \
-        NB_OVERRIDE(preferred_size, ctx);                                      \
+    ::nanogui::Vector2i preferred_size_impl(NVGcontext *ctx) const override {  \
+        NB_OVERRIDE(preferred_size_impl, ctx);                                 \
     }                                                                          \
     void perform_layout(NVGcontext *ctx) override {                            \
         NB_OVERRIDE(perform_layout, ctx);                                      \

include/nanogui/screen.h

@@ -249,9 +249,6 @@ class NANOGUI_EXPORT Screen : public Widget {
     void set_shutdown_glfw(bool v) { m_shutdown_glfw = v; }
     bool shutdown_glfw() { return m_shutdown_glfw; }
 
-    /// Is a tooltip currently fading in?
-    bool tooltip_fade_in_progress() const;
-
     using Widget::perform_layout;
 
     /// Compute the layout of all widgets
@@ -331,6 +328,10 @@ class NANOGUI_EXPORT Screen : public Widget {
     std::function<void(Vector2i)> m_resize_callback;
     RunMode m_last_run_mode;
     ref<Texture> m_depth_stencil_texture;
+
+    double m_tooltip_delay = 0.2;
+    bool m_tooltip_redraw_required = false;
+    void *m_tooltip_redraw_notify_thread;
 #if defined(NANOGUI_USE_METAL)
     void *m_metal_texture = nullptr;
     void *m_metal_drawable = nullptr;

include/nanogui/slider.h

@@ -43,7 +43,10 @@ class NANOGUI_EXPORT Slider : public Widget {
     const std::function<void(float)> &final_callback() const { return m_final_callback; }
     void set_final_callback(const std::function<void(float)> &callback) { m_final_callback = callback; }
 
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
+protected:
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
+
+public:
     virtual bool mouse_drag_event(const Vector2i &p, const Vector2i &rel, int button, int modifiers) override;
     virtual bool mouse_button_event(const Vector2i &p, int button, bool down, int modifiers) override;
     virtual void draw(NVGcontext* ctx) override;

include/nanogui/tabwidget.h

@@ -60,19 +60,19 @@ class NANOGUI_EXPORT TabWidgetBase : public Widget {
     /// Return the caption of the tab with the given ID
     const std::string& tab_caption(int id) const { return m_tab_captions[tab_index(id)]; }
     /// Change the caption of the tab with the given ID
-    void set_tab_caption(int id, std::string_view caption) { m_tab_captions[tab_index(id)] = caption; }
+    void set_tab_caption(int id, std::string_view caption) { m_tab_captions[tab_index(id)] = caption; preferred_size_changed(); }
 
     /// Return whether tabs provide a close button
     bool tabs_closeable() const { return m_tabs_closeable; }
-    void set_tabs_closeable(bool value) { m_tabs_closeable = value; }
+    void set_tabs_closeable(bool value) { m_tabs_closeable = value; preferred_size_changed(); }
 
     /// Return whether tabs can be dragged to different positions
     bool tabs_draggable() const { return m_tabs_draggable; }
     void set_tabs_draggable(bool value) { m_tabs_draggable = value; }
 
     /// Return the padding between the tab widget boundary and child widgets
     int padding() const { return m_padding; }
-    void set_padding(int value) { m_padding = value; }
+    void set_padding(int value) { m_padding = value; preferred_size_changed(); }
 
     /// Set the widget's background color (a global property)
     void set_background_color(const Color &background_color) {
@@ -101,7 +101,6 @@ class NANOGUI_EXPORT TabWidgetBase : public Widget {
 
     // Widget implementation
     virtual void perform_layout(NVGcontext* ctx) override;
-    virtual Vector2i preferred_size(NVGcontext* ctx) const override;
     virtual void draw(NVGcontext* ctx) override;
     virtual bool mouse_button_event(const Vector2i &p, int button, bool down,
                                     int modifiers) override;
@@ -110,6 +109,7 @@ class NANOGUI_EXPORT TabWidgetBase : public Widget {
                                     int modifiers) override;
 
 protected:
+    virtual Vector2i preferred_size_impl(NVGcontext* ctx) const override;
     std::pair<int, bool> tab_at_position(const Vector2i &p,
                                          bool test_vertical = true) const;
     virtual void update_visibility();
@@ -198,8 +198,8 @@ class NANOGUI_EXPORT TabWidget : public TabWidgetBase {
     void set_remove_children(bool value) { m_remove_children = value; }
 
     virtual void perform_layout(NVGcontext* ctx) override;
-    virtual Vector2i preferred_size(NVGcontext* ctx) const override;
 protected:
+    virtual Vector2i preferred_size_impl(NVGcontext* ctx) const override;
     virtual void update_visibility() override;
 protected:
     std::vector<std::pair<int, Widget *>> m_widgets;

include/nanogui/textarea.h

@@ -66,7 +66,7 @@ class NANOGUI_EXPORT TextArea : public Widget {
     }
 
     /// Set the amount of padding to add around the text
-    void set_padding(int padding) { m_padding = padding; }
+    void set_padding(int padding) { m_padding = padding; preferred_size_changed(); }
 
     /// Return the amount of padding that is added around the text
     int padding() const { return m_padding; }
@@ -90,14 +90,14 @@ class NANOGUI_EXPORT TextArea : public Widget {
 
     /* Widget implementation */
     virtual void draw(NVGcontext *ctx) override;
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
     virtual bool mouse_button_event(const Vector2i &p, int button, bool down,
                                     int modifiers) override;
     virtual bool mouse_drag_event(const Vector2i &p, const Vector2i &rel, int button,
                                   int modifiers) override;
     virtual bool keyboard_event(int key, int scancode, int action, int modifiers) override;
 
 protected:
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
     Vector2i position_to_block(const Vector2i &pos) const;
     Vector2i block_to_position(const Vector2i &pos) const;
 

include/nanogui/textbox.h

@@ -46,10 +46,20 @@ class NANOGUI_EXPORT TextBox : public Widget {
     void set_editable(bool editable);
 
     bool spinnable() const { return m_spinnable; }
-    void set_spinnable(bool spinnable) { m_spinnable = spinnable; }
+    void set_spinnable(bool spinnable) {
+        if (m_spinnable != spinnable) {
+            m_spinnable = spinnable;
+            preferred_size_changed();
+        }
+    }
 
     const std::string &value() const { return m_value; }
-    void set_value(std::string_view value) { m_value = value; }
+    void set_value(std::string_view value) {
+        if (m_value != value) {
+            m_value = value;
+            preferred_size_changed();
+        }
+    }
 
     std::string_view default_value() const { return m_default_value; }
     void set_default_value(std::string_view default_value) { m_default_value = default_value; }
@@ -58,10 +68,20 @@ class NANOGUI_EXPORT TextBox : public Widget {
     void set_alignment(Alignment align) { m_alignment = align; }
 
     std::string_view units() const { return m_units; }
-    void set_units(std::string_view units) { m_units = units; }
+    void set_units(std::string_view units) {
+        if (m_units != units) {
+            m_units = units;
+            preferred_size_changed();
+        }
+    }
 
     int units_image() const { return m_units_image; }
-    void set_units_image(int image) { m_units_image = image; }
+    void set_units_image(int image) {
+        if (m_units_image != image) {
+            m_units_image = image;
+            preferred_size_changed();
+        }
+    }
 
     /// Return the underlying regular expression specifying valid formats
     std::string_view format() const { return m_format; }
@@ -71,7 +91,12 @@ class NANOGUI_EXPORT TextBox : public Widget {
     /// Return the placeholder text to be displayed while the text box is empty.
     std::string_view placeholder() const { return m_placeholder; }
     /// Specify a placeholder text to be displayed while the text box is empty.
-    void set_placeholder(std::string_view placeholder) { m_placeholder = placeholder; }
+    void set_placeholder(std::string_view placeholder) {
+        if (m_placeholder != placeholder) {
+            m_placeholder = placeholder;
+            preferred_size_changed();
+        }
+    }
 
     /// Set the \ref Theme used to draw this widget
     virtual void set_theme(Theme *theme) override;
@@ -111,7 +136,10 @@ class NANOGUI_EXPORT TextBox : public Widget {
     virtual bool keyboard_event(int key, int scancode, int action, int modifiers) override;
     virtual bool keyboard_character_event(unsigned int codepoint) override;
 
-    virtual Vector2i preferred_size(NVGcontext *ctx) const override;
+protected:
+    virtual Vector2i preferred_size_impl(NVGcontext *ctx) const override;
+
+public:
     virtual void draw(NVGcontext* ctx) override;
 protected:
     bool check_format(const std::string &input, const std::string &format);