flutter::StopwatchVisualizer Class Reference

Abstract class for visualizing (i.e. drawing) a stopwatch. More...

#include <stopwatch.h>

Inheritance diagram for flutter::StopwatchVisualizer:

Public Member Functions
	StopwatchVisualizer (const Stopwatch &stopwatch)
virtual	~StopwatchVisualizer ()=default
virtual void	Visualize (DlCanvas *canvas, const SkRect &rect) const =0
	Renders the stopwatch as a graph.
	FML_DISALLOW_COPY_AND_ASSIGN (StopwatchVisualizer)

Protected Member Functions
double	UnitFrameInterval (double time_ms) const
	Converts a raster time to a unit interval.
double	UnitHeight (double time_ms, double max_height) const
	Converts a raster time to a unit height.
fml::Milliseconds	GetFrameBudget () const

Protected Attributes
const Stopwatch &	stopwatch_
fml::Milliseconds	frame_budget_

Detailed Description

Abstract class for visualizing (i.e. drawing) a stopwatch.

Note

This was originally folded into the |Stopwatch| class, but was separated out to make it easier to change the underlying implementation (which relied directly on Skia, not showing on Impeller: https://github.com/flutter/flutter/issues/126009).

Definition at line 93 of file stopwatch.h.

Constructor & Destructor Documentation

StopwatchVisualizer()

flutter::StopwatchVisualizer::StopwatchVisualizer ( const Stopwatch &  stopwatch )

inlineexplicit

Definition at line 95 of file stopwatch.h.

      : stopwatch_(stopwatch) {
    // Looking up the frame budget from the stopwatch delegate class may call
    // into JNI or make platform calls which are slow. This value is safe to
    // cache since the StopwatchVisualizer is recreated on each frame.
    frame_budget_ = stopwatch_.GetFrameBudget();
  }

~StopwatchVisualizer()

virtual flutter::StopwatchVisualizer::~StopwatchVisualizer ( )

virtualdefault

Member Function Documentation

FML_DISALLOW_COPY_AND_ASSIGN()

flutter::StopwatchVisualizer::FML_DISALLOW_COPY_AND_ASSIGN

(

StopwatchVisualizer

)

GetFrameBudget()

fml::Milliseconds flutter::StopwatchVisualizer::GetFrameBudget ( ) const

inlineprotected

Definition at line 120 of file stopwatch.h.

{ return frame_budget_; }

UnitFrameInterval()

double flutter::StopwatchVisualizer::UnitFrameInterval ( double  time_ms ) const

protected

Converts a raster time to a unit interval.

Definition at line 57 of file stopwatch.cc.

                                                                         {
  return raster_time_ms / frame_budget_.count();
}

UnitHeight()

double flutter::StopwatchVisualizer::UnitHeight ( double  time_ms, double  max_height  ) const

protected

Converts a raster time to a unit height.

Definition at line 61 of file stopwatch.cc.

                                                                       {
  double unit_height = UnitFrameInterval(raster_time_ms) / max_unit_interval;
  if (unit_height > 1.0) {
    unit_height = 1.0;
  }
  return unit_height;
}

Visualize()

virtual void flutter::StopwatchVisualizer::Visualize ( DlCanvas *  canvas, const SkRect &  rect  ) const

pure virtual

Renders the stopwatch as a graph.

Parameters

	canvas	The canvas to draw on.
[in]	rect	The rectangle to draw in.

Implemented in flutter::DlStopwatchVisualizer, and flutter::SkStopwatchVisualizer.

Member Data Documentation

frame_budget_

fml::Milliseconds flutter::StopwatchVisualizer::frame_budget_

protected

Definition at line 123 of file stopwatch.h.

stopwatch_

const Stopwatch& flutter::StopwatchVisualizer::stopwatch_

protected

Definition at line 122 of file stopwatch.h.

---

The documentation for this class was generated from the following files:

• flow/stopwatch.h
• flow/stopwatch.cc