diff --git a/CHANGELOG.md b/CHANGELOG.md
index ff58bed3..63de88c1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
### Added
- `Ferrum::Page#disable_javascript` disables the JavaScript from the HTML source
+- `Ferrum::Page#set_viewport` emulates the viewport
### Changed
diff --git a/README.md b/README.md
index 8411cb66..bdfa442f 100644
--- a/README.md
+++ b/README.md
@@ -922,6 +922,21 @@ browser.disable_javascript
```
+#### set_viewport
+
+Overrides device screen dimensions and emulates viewport.
+
+* options `Hash`
+ * :width `Integer`, viewport width. `0` by default
+ * :height `Integer`, viewport height. `0` by default
+ * :scale_factor `Float`, device scale factor. `0` by default
+ * :mobile `Boolean`, whether to emulate mobile device. `false` by default
+
+```ruby
+browser.set_viewport(width: 1000, height: 600, scale_factor: 3)
+```
+
+
## Frames
#### frames : `Array[Frame] | []`
diff --git a/lib/ferrum/browser.rb b/lib/ferrum/browser.rb
index 89cfa65d..6dd5c0af 100644
--- a/lib/ferrum/browser.rb
+++ b/lib/ferrum/browser.rb
@@ -28,7 +28,7 @@ class Browser
add_script_tag add_style_tag bypass_csp
on position position=
playback_rate playback_rate=
- disable_javascript] => :page
+ disable_javascript set_viewport] => :page
delegate %i[default_user_agent] => :process
attr_reader :client, :process, :contexts, :options, :window_size, :base_url
diff --git a/lib/ferrum/page.rb b/lib/ferrum/page.rb
index 08d4d3c5..46ea4720 100644
--- a/lib/ferrum/page.rb
+++ b/lib/ferrum/page.rb
@@ -133,6 +133,30 @@ def close
@client.close
end
+ #
+ # Overrides device screen dimensions and emulates viewport according to parameters
+ #
+ # Read more [here](https://chromedevtools.github.io/devtools-protocol/tot/Emulation/#method-setDeviceMetricsOverride).
+ #
+ # @param [Integer] width width value in pixels. 0 disables the override
+ #
+ # @param [Integer] height height value in pixels. 0 disables the override
+ #
+ # @param [Float] scale_factor device scale factor value. 0 disables the override
+ #
+ # @param [Boolean] mobile whether to emulate mobile device
+ #
+ def set_viewport(width:, height:, scale_factor: 0, mobile: false)
+ command(
+ "Emulation.setDeviceMetricsOverride",
+ slowmoable: true,
+ width: width,
+ height: height,
+ deviceScaleFactor: scale_factor,
+ mobile: mobile
+ )
+ end
+
def resize(width: nil, height: nil, fullscreen: false)
if fullscreen
width, height = document_size
@@ -142,11 +166,7 @@ def resize(width: nil, height: nil, fullscreen: false)
set_window_bounds(width: width, height: height)
end
- command("Emulation.setDeviceMetricsOverride", slowmoable: true,
- width: width,
- height: height,
- deviceScaleFactor: 0,
- mobile: false)
+ set_viewport(width: width, height: height)
end
#
diff --git a/spec/page_spec.rb b/spec/page_spec.rb
index ecddd314..8d6d0e26 100644
--- a/spec/page_spec.rb
+++ b/spec/page_spec.rb
@@ -186,4 +186,13 @@
expect(page.main_frame.body).to eq("text
")
end
end
+
+ describe "#set_viewport" do
+ it "overrides the viewport size" do
+ page.set_viewport(width: 500, height: 300, scale_factor: 2)
+
+ expect(page.viewport_size).to eq([500, 300])
+ expect(page.device_pixel_ratio).to eq(2)
+ end
+ end
end
diff --git a/spec/support/views/initial_alert.erb b/spec/support/views/initial_alert.erb
deleted file mode 100644
index 5c61d95c..00000000
--- a/spec/support/views/initial_alert.erb
+++ /dev/null
@@ -1,11 +0,0 @@
-
-
-
-
- Initial alert page
-
-
-
-