I can't make it fit the RectTransform.

[AzadNezamdoust]

Set margins is not relative to the canvas so based on screen size it does not fit in my ui.

[KojiNakamaru]

In the sample app, if you place an Image as below, You can compute the bounds and get corresponding margins as below:

diff --git a/sample/Assets/Scripts/SampleWebView.cs b/sample/Assets/Scripts/SampleWebView.cs
index 5cc08c5..beea224 100644
--- a/sample/Assets/Scripts/SampleWebView.cs
+++ b/sample/Assets/Scripts/SampleWebView.cs
@@ -31,6 +31,19 @@ public class SampleWebView : MonoBehaviour
     public Text status;
     WebViewObject webViewObject;

+    // cf. https://answers.unity.com/questions/1013011/convert-recttransform-rect-to-screen-space.html?childToView=1628573#answer-1628573
+    public static Bounds GetRectTransformBounds(RectTransform transform)
+    {
+        var corners = new Vector3[4];
+        transform.GetWorldCorners(corners);
+        var bounds = new Bounds(corners[0], Vector3.zero);
+        for (var i = 1; i < 4; i++)
+        {
+            bounds.Encapsulate(corners[i]);
+        }
+        return bounds;
+    }
+
     IEnumerator Start()
     {
         webViewObject = (new GameObject("WebViewObject")).AddComponent<WebViewObject>();
@@ -109,7 +122,13 @@ public class SampleWebView : MonoBehaviour
 #endif
         //webViewObject.SetAlertDialogEnabled(false);
         //webViewObject.SetURLPattern("", "^https://.*youtube.com", "^https://.*google.com");
-        webViewObject.SetMargins(5, 100, 5, Screen.height / 4);
+        var bounds = GetRectTransformBounds(GameObject.Find("Image").GetComponent<RectTransform>());
+        Debug.Log(bounds);
+        webViewObject.SetMargins(
+            (int)bounds.min.x,
+            (int)bounds.min.y,
+            (int)(Screen.width - bounds.max.x),
+            (int)(Screen.height - bounds.max.y));
         webViewObject.SetVisibility(true);

 #if !UNITY_WEBPLAYER && !UNITY_WEBGL

[AzadNezamdoust]

Here is the final version of the margin finder. The one you described a bow does not calculate it right.

` Rect newSafeArea = Screen.safeArea;

        Vector2 _anchorMin = newSafeArea.position;
        Vector2 _anchorMax = newSafeArea.position + newSafeArea.size;

        if (_safeAreaX)
        {
            _anchorMin.x /= Screen.width;
            _anchorMax.x /= Screen.width;
        }
        if (_safeAreaY)
        {
            _anchorMin.y /= Screen.height;
            _anchorMax.y /= Screen.height;
        }

        _webViewObject.SetMargins(new Vector4(
            _anchorMin.x * Screen.width,
            (1 - _anchorMax.y) * Screen.height,
            (1 - _anchorMax.x) * Screen.width,
            _anchorMin.y * Screen.height));`

[KojiNakamaru]

Thanks, in my version, at least top/bottom margins should be flipped. Here is correct one:

diff --git a/sample/Assets/Scripts/SampleWebView.cs b/sample/Assets/Scripts/SampleWebView.cs
index 1380fe8..63b9fcb 100644
--- a/sample/Assets/Scripts/SampleWebView.cs
+++ b/sample/Assets/Scripts/SampleWebView.cs
@@ -31,6 +31,19 @@ public class SampleWebView : MonoBehaviour
     public Text status;
     WebViewObject webViewObject;

+    // cf. https://answers.unity.com/questions/1013011/convert-recttransform-rect-to-screen-space.html?childToView=1628573#answer-1628573
+    public static Bounds GetRectTransformBounds(RectTransform transform)
+    {
+        var corners = new Vector3[4];
+        transform.GetWorldCorners(corners);
+        var bounds = new Bounds(corners[0], Vector3.zero);
+        for (var i = 1; i < 4; i++)
+        {
+            bounds.Encapsulate(corners[i]);
+        }
+        return bounds;
+    }
+
     IEnumerator Start()
     {
         webViewObject = (new GameObject("WebViewObject")).AddComponent<WebViewObject>();
@@ -122,7 +135,16 @@ public class SampleWebView : MonoBehaviour
         // Add BASIC authentication feature (Android and iOS with WKWebView only) by takeh1k0 · Pull Request #570 · gree/unity-webview
         //webViewObject.SetBasicAuthInfo("id", "password");

-        webViewObject.SetMargins(5, 100, 5, Screen.height / 4);
+        // webViewObject.SetMargins(5, 100, 5, Screen.height / 4);
+        var bounds = GetRectTransformBounds(GameObject.Find("Image").GetComponent<RectTransform>());
+        Debug.Log(Screen.width);
+        Debug.Log(Screen.height);
+        Debug.Log(bounds);
+        webViewObject.SetMargins(
+            (int)bounds.min.x,
+            (int)(Screen.height - bounds.max.y),
+            (int)(Screen.width - bounds.max.x),
+            (int)bounds.min.y);
         webViewObject.SetVisibility(true);

 #if !UNITY_WEBPLAYER && !UNITY_WEBGL

As you did, another tweak might be necessary depending on the setting of Render outside safe area.

[xinbot]

I have questions about fitting theRecttransform. Here the SetMargins() method seem to be accepting values in pixel unit. I check the unity documentation and confirm that Screen.height and Screen.width are in pixel unit. However, the values inside Bounds value is in point unit (I think the inside unity there are some metric definding point unit), so the substraction from pixel unit and point unit doesn't seem to be right. Shouldn't we change both value into pixel unit before doing math and assign the values to SetMargins() method.

[KojiNakamaru]

cf. https://github.com/gree/unity-webview/pull/816#issuecomment-1179684293