From 14fb7e13fb272a43b9924d5d2823b0c105d781b0 Mon Sep 17 00:00:00 2001
From: Héctor Ramón Jiménez <hector0193@gmail.com>
Date: Thu, 5 Dec 2019 03:09:39 +0100
Subject: Place `TextInput` cursor position on click
---
native/src/renderer/null.rs | 4 ++
native/src/widget/text_input.rs | 78 ++++++++++++++++++++++++++++++++--
wgpu/src/renderer/widget/text_input.rs | 37 +++++++++-------
3 files changed, 100 insertions(+), 19 deletions(-)
diff --git a/native/src/renderer/null.rs b/native/src/renderer/null.rs
index da0e5159..02f033a5 100644
--- a/native/src/renderer/null.rs
+++ b/native/src/renderer/null.rs
@@ -89,6 +89,10 @@ impl text_input::Renderer for Null {
20
}
+ fn measure_value(&self, _value: &str, _size: u16) -> f32 {
+ 0.0
+ }
+
fn draw(
&mut self,
_bounds: Rectangle,
diff --git a/native/src/widget/text_input.rs b/native/src/widget/text_input.rs
index f97ed424..764f87cf 100644
--- a/native/src/widget/text_input.rs
+++ b/native/src/widget/text_input.rs
@@ -160,7 +160,7 @@ where
layout: Layout<'_>,
cursor_position: Point,
messages: &mut Vec<Message>,
- _renderer: &Renderer,
+ renderer: &Renderer,
) {
match event {
Event::Mouse(mouse::Event::Input {
@@ -170,8 +170,22 @@ where
self.state.is_focused =
layout.bounds().contains(cursor_position);
- if self.state.cursor_position(&self.value) == 0 {
- self.state.move_cursor_to_end(&self.value);
+ if self.state.is_focused {
+ let text_layout = layout.children().next().unwrap();
+ let target = cursor_position.x - text_layout.bounds().x;
+
+ if target < 0.0 {
+ self.state.cursor_position = 0;
+ } else {
+ self.state.cursor_position = find_cursor_position(
+ renderer,
+ target,
+ &self.value,
+ self.size.unwrap_or(renderer.default_size()),
+ 0,
+ self.value.len(),
+ );
+ }
}
}
Event::Keyboard(keyboard::Event::CharacterReceived(c))
@@ -275,6 +289,11 @@ pub trait Renderer: crate::Renderer + Sized {
/// [`TextInput`]: struct.TextInput.html
fn default_size(&self) -> u16;
+ /// Returns the width of the value of the [`TextInput`].
+ ///
+ /// [`TextInput`]: struct.TextInput.html
+ fn measure_value(&self, value: &str, size: u16) -> f32;
+
/// Draws a [`TextInput`].
///
/// It receives:
@@ -437,3 +456,56 @@ impl Value {
let _ = self.0.remove(index);
}
}
+
+// TODO: Reduce allocations
+fn find_cursor_position<Renderer: self::Renderer>(
+ renderer: &Renderer,
+ target: f32,
+ value: &Value,
+ size: u16,
+ start: usize,
+ end: usize,
+) -> usize {
+ if start >= end {
+ if start == 0 {
+ return 0;
+ }
+
+ let prev = value.until(start - 1);
+ let next = value.until(start);
+
+ let prev_width = renderer.measure_value(&prev.to_string(), size);
+ let next_width = renderer.measure_value(&next.to_string(), size);
+
+ if (target - next_width).abs() > (target - prev_width).abs() {
+ return start - 1;
+ } else {
+ return start;
+ }
+ }
+
+ let index = (end - start) / 2;
+ let subvalue = value.until(start + index);
+
+ let width = renderer.measure_value(&subvalue.to_string(), size);
+
+ if width > target {
+ find_cursor_position(
+ renderer,
+ target,
+ value,
+ size,
+ start,
+ start + index,
+ )
+ } else {
+ find_cursor_position(
+ renderer,
+ target,
+ value,
+ size,
+ start + index + 1,
+ end,
+ )
+ }
+}
diff --git a/wgpu/src/renderer/widget/text_input.rs b/wgpu/src/renderer/widget/text_input.rs
index d64fca6d..c6c64b88 100644
--- a/wgpu/src/renderer/widget/text_input.rs
+++ b/wgpu/src/renderer/widget/text_input.rs
@@ -12,6 +12,24 @@ impl text_input::Renderer for Renderer {
20
}
+ fn measure_value(&self, value: &str, size: u16) -> f32 {
+ let (mut width, _) = self.text_pipeline.measure(
+ value,
+ f32::from(size),
+ Font::Default,
+ Size::INFINITY,
+ );
+
+ let spaces_at_the_end = value.len() - value.trim_end().len();
+
+ if spaces_at_the_end > 0 {
+ let space_width = self.text_pipeline.space_width(size as f32);
+ width += spaces_at_the_end as f32 * space_width;
+ }
+
+ width
+ }
+
fn draw(
&mut self,
bounds: Rectangle,
@@ -48,7 +66,6 @@ impl text_input::Renderer for Renderer {
border_radius: 4,
};
- let size = f32::from(size);
let text = value.to_string();
let text_value = Primitive::Text {
@@ -68,7 +85,7 @@ impl text_input::Renderer for Renderer {
width: f32::INFINITY,
..text_bounds
},
- size,
+ size: f32::from(size),
horizontal_alignment: HorizontalAlignment::Left,
vertical_alignment: VerticalAlignment::Center,
};
@@ -77,20 +94,8 @@ impl text_input::Renderer for Renderer {
let text_before_cursor =
value.until(state.cursor_position(value)).to_string();
- let (mut text_value_width, _) = self.text_pipeline.measure(
- &text_before_cursor,
- size,
- Font::Default,
- Size::new(f32::INFINITY, text_bounds.height),
- );
-
- let spaces_at_the_end =
- text_before_cursor.len() - text_before_cursor.trim_end().len();
-
- if spaces_at_the_end > 0 {
- let space_width = self.text_pipeline.space_width(size);
- text_value_width += spaces_at_the_end as f32 * space_width;
- }
+ let text_value_width =
+ self.measure_value(&text_before_cursor, size);
let cursor = Primitive::Quad {
bounds: Rectangle {
--
cgit