Feat: Add Screencasting of the browser, save images. v0.15 compatible with Cuprite

lib/ferrum/browser.rb

@@ -22,6 +22,7 @@ class Browser
                 body doctype content=
                 headers cookies network downloads
                 mouse keyboard
+                start_screencast stop_screencast
                 screenshot pdf mhtml viewport_size device_pixel_ratio
                 frames frame_by main_frame
                 evaluate evaluate_on evaluate_async execute evaluate_func

lib/ferrum/page.rb

@@ -7,10 +7,12 @@
 require "ferrum/headers"
 require "ferrum/cookies"
 require "ferrum/dialog"
+require "ferrum/screencaster"
 require "ferrum/network"
 require "ferrum/downloads"
 require "ferrum/page/frames"
 require "ferrum/page/screenshot"
+require "ferrum/page/screencast"
 require "ferrum/page/animation"
 require "ferrum/page/tracing"
 require "ferrum/page/stream"
@@ -30,6 +32,7 @@ class Page
     include Screenshot
     include Frames
     include Stream
+    include Screencast
 
     attr_accessor :referrer
     attr_reader :context_id, :target_id, :event, :tracing
@@ -69,12 +72,16 @@ class Page
     # @return [Downloads]
     attr_reader :downloads
 
+    # Control Screencasting
+    #
+    # @return [nil]
+    attr_reader :screencaster
+
     def initialize(client, context_id:, target_id:, proxy: nil)
       @client = client
       @context_id = context_id
       @target_id = target_id
       @options = client.options
-
       @frames = Concurrent::Map.new
       @main_frame = Frame.new(nil, self)
       @event = Utils::Event.new.tap(&:set)
@@ -87,6 +94,7 @@ def initialize(client, context_id:, target_id:, proxy: nil)
       @network = Network.new(self)
       @tracing = Tracing.new(self)
       @downloads = Downloads.new(self)
+      @screencaster = Screencaster.new(self)
 
       subscribe
       prepare_page
@@ -374,6 +382,10 @@ def on(name, &block)
           request = Network::AuthRequest.new(self, params)
           block.call(request, index, total)
         end
+      when :screencastFrame
+        @client.on("Page.screencastFrame") do |params, index, total|
+          block.call(params, index, total)
+        end
       else
         client.on(name, &block)
       end
@@ -425,6 +437,10 @@ def subscribe
           dialog.accept
         end
       end
+
+      on(:screencastFrame) do |params, _index, _total|
+        @screencaster.add_frame(params)
+      end
     end
 
     def prepare_page

lib/ferrum/page/screencast.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+require "ferrum/screencaster"
+
+module Ferrum
+  class Page
+    module Screencast
+      attr_reader :screencaster
+
+      def start_screencast(...)
+        @screencaster.start_screencast(...)
+      end
+
+      def stop_screencast
+        @screencaster.stop_screencast
+      end
+    end
+  end
+end

lib/ferrum/screencaster.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+require 'fileutils'
+
+# Combine the resulting frames together into a video with:
+# ffmpeg -y -framerate 30 -i 'frame-%d.jpeg' -c:v libx264 -r 30 -pix_fmt yuv420p try2.mp4
+#
+module Ferrum
+  class Screencaster
+    def initialize(page)
+      @page = page
+      @frame_number = 0
+      @threads = []
+      @save_path
+    end
+
+    def add_frame(params)
+      @page.command("Page.screencastFrameAck", sessionId: params["sessionId"])
+
+      t = Thread.new { File.binwrite("#{@save_path}/frame-#{@frame_number}.jpeg", Base64.decode64(params["data"])) }
+      @frame_number += 1
+      @threads << t
+      true
+    end
+
+
+		# save_path: Directory where individual frames from the screencast will be saved
+    def start_screencast(save_path)
+      @save_path = save_path
+      raise "Save path for screen recording does not exist" unless Dir.exist?(@save_path)
+      @page.command("Page.startScreencast", format: "jpeg")
+    end
+
+    def stop_screencast
+      @threads.each(&:join)
+      @page.command("Page.stopScreencast")
+    end
+  end
+end