feat(PdfReader): support Watermark component (#405)

* PDF阅读器水印内容仅在全屏演示状态显示 #5811

* WatermarkDemoModeOnly  当全局水印（Watermark IsPage="true"）时, 也会自动启用,无需手动设置

---------

Co-authored-by: Argo Zhang <argo@live.ca>

Author: densen2014

src/components/BootstrapBlazor.PdfReader/PdfReader.razor.cs

@@ -131,6 +131,12 @@ public partial class PdfReader : IAsyncDisposable
     [Parameter]
     public string? Watermark { get; set; }
 
+    /// <summary>
+    /// 获得/设置 水印内容仅在全屏演示状态显示
+    /// </summary> 
+    [Parameter]
+    public bool WatermarkDemoModeOnly { get; set; }
+
     /// <summary>
     /// Debug
     /// </summary>
@@ -184,6 +190,10 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
             var userAgent = await Module!.InvokeAsync<string>("getUserAgent");
             var parser = Parser.GetDefault();
             ClientInfo = parser.Parse(userAgent);
+            if (!WatermarkDemoModeOnly)
+            { 
+                WatermarkDemoModeOnly = await Module.InvokeAsync<bool>("getGlobalWatermark");
+            }
             await Refresh();
         }
     }
@@ -291,7 +301,7 @@ public virtual async Task Refresh(string? search = null, int? page = null, EnumP
 
     }
 
-    private string GenUrl(bool filemode = true) => $"{ViewerBase}?file={(filemode ? HttpUtility.UrlEncode(FileName) : "(1)")}#page={Page}&navpanes={(Navpanes ? 0 : 1)}&toolbar={(Toolbar ? 0 : 1)}&statusbar={(Statusbar ? 0 : 1)}&pagemode={(Pagemode ?? EnumPageMode.Thumbs).ToString().ToLower()}&search={Search}" + (Zoom != null ? $"&zoom={Zoom.GetEnumName()}" : "") + (Watermark != null ? $"&wm={Watermark}" : "");
+    private string GenUrl(bool filemode = true) => $"{ViewerBase}?file={(filemode ? HttpUtility.UrlEncode(FileName) : "(1)")}#page={Page}&navpanes={(Navpanes ? 0 : 1)}&toolbar={(Toolbar ? 0 : 1)}&statusbar={(Statusbar ? 0 : 1)}&pagemode={(Pagemode ?? EnumPageMode.Thumbs).ToString().ToLower()}&search={Search}" + (Zoom != null ? $"&zoom={Zoom.GetEnumName()}" : "") + (Watermark != null ? $"&wm={Watermark}" : "") + (WatermarkDemoModeOnly ? $"&wmonlydemo=true" : "");
 
 
     /// <summary>

src/components/BootstrapBlazor.PdfReader/wwwroot/app.js

@@ -8,10 +8,6 @@ export async function showPdf(baseurl, element, stream) {
     const urlblob = URL.createObjectURL(blob);
     element.src = baseurl.replace('(1)',  urlblob);
 }
-export function setWatermark(watermark, element) {
-    console.log(element.contentWindow.document)
-    var elmnt = element.contentWindow.document.getElementById("watermark");
-    //elmnt.style.display = "none";
-    //var d = y.getElementById("watermark");
-    //y.getElementById("watermark").value = watermark;
-}
+export function getGlobalWatermark() {
+    return document.body.getAttribute('data-bb-watermark') == 'true';
+} 

src/components/BootstrapBlazor.PdfReader/wwwroot/web/limit.js

@@ -17,8 +17,19 @@ function onBodyLoad() {
     }
 
     if (getQueryVariable("wm"))
-    { 
-        document.getElementById("watermark").value = getQueryVariable("wm");
+    {
+        if (getQueryVariable("wmonlydemo") && getQueryVariable("wmonlydemo")=='true')
+        {
+            document.addEventListener('fullscreenchange', () => {
+                if (document.fullscreenElement === document.getElementById("viewerContainer") ) {
+                    document.getElementById("watermark").value = getQueryVariable("wm");
+                } else {
+                    document.getElementById("watermark").value = '';
+                }
+            });
+        } else {
+            document.getElementById("watermark").value = getQueryVariable("wm");
+        }
     }
 }
 
@@ -31,4 +42,4 @@ function getQueryVariable(variable) {
         if (pair[0] == variable) { return pair[1]; }
     }
     return (false);
-}
+}