Shrink handwriting when not focused [wip]

src/handwriting/mod.rs

@@ -27,7 +27,7 @@ use zerocopy::{FromBytes, IntoBytes};
 use crate::{custom_code_block::try_from_custom_code_block, rasterizer};
 use crate::{custom_code_block::write_custom_code_block, util::random_id};
 
-use self::tool::{Tool, ToolEvent};
+use self::tool::{ToolEvent, Tool};
 
 const HANDWRITING_MIN_HEIGHT: f32 = 100.0;
 const HANDWRITING_BOTTOM_PADDING: f32 = 80.0;
@@ -89,6 +89,9 @@ struct Ephemeral {
     /// Tool position last frame, in canvas space.
     last_tool_position: Option<Pos2>,
 
+    /// Whether the handwriting element is being interacted with.
+    is_focused: bool,
+
     /// The stroke that is currently being drawed.
     current_stroke: Vec<Pos2>,
 
@@ -139,9 +142,10 @@ impl Default for Ephemeral {
         Self {
             id: random_id(),
             canvas_rasterizer: Default::default(),
-            tool: Tool::Pencil,
+            tool: Tool::Eraser,
             tool_position: None,
             last_tool_position: None,
+            is_focused: false,
             current_stroke: Default::default(),
             tessellator: None,
             mesh: Default::default(),
@@ -238,9 +242,16 @@ impl Handwriting {
         // Was the user in the process of drawing a stroke last frame?
         let was_drawing = !self.e.current_stroke.is_empty();
 
-        // Is the user in the process of drawing a stroke now?
+        // Is the user in the process of drawing a stroke now?;
         let is_drawing = response.interact_pointer_pos().is_some();
 
+        if is_drawing {
+            self.e.is_focused = true;
+        } else if ui.ctx().input(|i| i.pointer.any_down()) {
+            // if the user starts interactive with something else, unfocus the handwriting area.
+            self.e.is_focused = false;
+        }
+
         if !is_drawing {
             if was_drawing {
                 // commit current line
@@ -248,12 +259,18 @@ impl Handwriting {
                 response.mark_changed();
             }
 
+            let padding = if self.e.is_focused {
+                HANDWRITING_BOTTOM_PADDING
+            } else {
+                0.0
+            };
+
             // recalculate how tall the widget should be
             let lines_max_y = self
                 .strokes
                 .iter()
                 .flatten()
-                .map(|p| p.y + HANDWRITING_BOTTOM_PADDING)
+                .map(|p| p.y + padding)
                 .fold(HANDWRITING_MIN_HEIGHT, |max, y| max.max(y));
 
             // Change the height of the handwriting item.
@@ -299,7 +316,9 @@ impl Handwriting {
                     self.e.tool_position = tool_event.position();
                     match self.e.tool {
                         Tool::Pencil => {
-                            hw_response.changed |= tool::pencil::on_tool_event(self, tool_event);
+                            hw_response.changed |=
+                            tool::pencil::on_tool_event(self, tool_event);
+                            
                         }
                         Tool::Eraser => {
                             if tool::eraser::on_tool_event(self, tool_event) {
@@ -365,9 +384,7 @@ impl Handwriting {
         // Draw the texture
         self.e.canvas_rasterizer.show(ui.ctx(), &painter, mesh_rect);
 
-        if let Some(tool_position) = self.e.tool_position
+        if let Some(tool_position) = self.e.tool_position && let Tool::Eraser = self.e.tool {
-            && let Tool::Eraser = self.e.tool
-        {
             let pos = to_screen * tool_position;
             let shape = Shape::circle_stroke(pos, tool::eraser::RADIUS, style.stroke);
             painter.add(shape);