Implement alert dialogs

Fixed conflict

Fixed merge issue

Finished implementation

Disable tinyfiledialogs on Windows

addressed comments

Use ancestor's SubpageId
Move display alert from method to function
Add extra test for nested iframes

Addressed comments

Updated tinyfiledialogs

Author: cbrewster

components/compositing/constellation.rs

@@ -797,6 +797,10 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
                 debug!("constellation got SetDocumentState message");
                 self.document_states.insert(pipeline_id, state);
             }
+            Request::Script(FromScriptMsg::Alert(pipeline_id, message, sender)) => {
+                debug!("constellation got Alert message");
+                self.handle_alert(pipeline_id, message, sender);
+            }
 
 
             // Messages from layout thread
@@ -1069,6 +1073,44 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
         }
     }
 
+    fn handle_alert(&mut self, pipeline_id: PipelineId, message: String, sender: IpcSender<bool>) {
+        let display_alert_dialog = if prefs::get_pref("dom.mozbrowser.enabled").as_boolean().unwrap_or(false) {
+            let parent_pipeline_info = self.pipelines.get(&pipeline_id).and_then(|source| source.parent_info);
+            if let Some(_) = parent_pipeline_info {
+                let root_pipeline_id = self.root_frame_id
+                    .and_then(|root_frame_id| self.frames.get(&root_frame_id))
+                    .map(|root_frame| root_frame.current);
+
+                let ancestor_info = self.get_root_pipeline_and_containing_parent(&pipeline_id);
+                if let Some(ancestor_info) = ancestor_info {
+                    if root_pipeline_id == Some(ancestor_info.0) {
+                        match root_pipeline_id.and_then(|pipeline_id| self.pipelines.get(&pipeline_id)) {
+                            Some(root_pipeline) => {
+                                // https://developer.mozilla.org/en-US/docs/Web/Events/mozbrowsershowmodalprompt
+                                let event = MozBrowserEvent::ShowModalPrompt("alert".to_owned(), "Alert".to_owned(),
+                                                                             String::from(message), "".to_owned());
+                                root_pipeline.trigger_mozbrowser_event(ancestor_info.1, event);
+                            }
+                            None => return warn!("Alert sent to Pipeline {:?} after closure.", root_pipeline_id),
+                        }
+                    } else {
+                        warn!("A non-current frame is trying to show an alert.")
+                    }
+                }
+                false
+            } else {
+                true
+            }
+        } else {
+            true
+        };
+
+        let result = sender.send(display_alert_dialog);
+        if let Err(e) = result {
+            self.handle_send_error(pipeline_id, e);
+        }
+    }
+
     fn handle_load_url_msg(&mut self, source_id: PipelineId, load_data: LoadData) {
         self.load_url(source_id, load_data);
     }
@@ -1945,6 +1987,29 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
         }
     }
 
+    /// For a given pipeline, determine the iframe in the root pipeline that transitively contains
+    /// it. There could be arbitrary levels of nested iframes in between them.
+    fn get_root_pipeline_and_containing_parent(&self, pipeline_id: &PipelineId) -> Option<(PipelineId, SubpageId)> {
+        if let Some(pipeline) = self.pipelines.get(pipeline_id) {
+            if let Some(mut ancestor_info) = pipeline.parent_info {
+                if let Some(mut ancestor) = self.pipelines.get(&ancestor_info.0) {
+                    while let Some(next_info) = ancestor.parent_info {
+                        ancestor_info = next_info;
+                        ancestor = match self.pipelines.get(&ancestor_info.0) {
+                            Some(ancestor) => ancestor,
+                            None => {
+                                warn!("Get parent pipeline before root via closed pipeline {:?}.", ancestor_info.0);
+                                return None;
+                            },
+                        };
+                    }
+                    return Some(ancestor_info);
+                }
+            }
+        }
+        None
+    }
+
     // https://developer.mozilla.org/en-US/docs/Web/Events/mozbrowserlocationchange
     // Note that this is a no-op if the pipeline is not an immediate child iframe of the root
     fn trigger_mozbrowserlocationchange(&self, pipeline_id: PipelineId) {
@@ -1976,19 +2041,15 @@ impl<LTF: LayoutThreadFactory, STF: ScriptThreadFactory> Constellation<LTF, STF>
     fn trigger_mozbrowsererror(&self, pipeline_id: PipelineId, reason: String, backtrace: String) {
         if !prefs::get_pref("dom.mozbrowser.enabled").as_boolean().unwrap_or(false) { return; }
 
-        if let Some(pipeline) = self.pipelines.get(&pipeline_id) {
-            if let Some(mut ancestor_info) = pipeline.parent_info {
-                if let Some(mut ancestor) = self.pipelines.get(&ancestor_info.0) {
-                    while let Some(next_info) = ancestor.parent_info {
-                        ancestor_info = next_info;
-                        ancestor = match self.pipelines.get(&ancestor_info.0) {
-                            Some(ancestor) => ancestor,
-                            None => return warn!("Mozbrowsererror via closed pipeline {:?}.", ancestor_info.0),
-                        };
-                    }
+        let ancestor_info = self.get_root_pipeline_and_containing_parent(&pipeline_id);
+
+        if let Some(ancestor_info) = ancestor_info {
+            match self.pipelines.get(&ancestor_info.0) {
+                Some(ancestor) => {
                     let event = MozBrowserEvent::Error(MozBrowserErrorType::Fatal, Some(reason), Some(backtrace));
                     ancestor.trigger_mozbrowser_event(ancestor_info.1, event);
-                }
+                },
+                None => return warn!("Mozbrowsererror via closed pipeline {:?}.", ancestor_info.0),
             }
         }
     }

components/script/Cargo.toml

@@ -13,6 +13,9 @@ path = "lib.rs"
 [features]
 debugmozjs = ['js/debugmozjs']
 
+[target.'cfg(any(target_os = "macos", target_os = "linux"))'.dependencies]
+tinyfiledialogs = {git = "https://github.com/jdm/tinyfiledialogs"}
+
 [dependencies]
 plugins = {path = "../plugins"}
 util = {path = "../util"}

components/script/dom/window.rs

@@ -59,7 +59,7 @@ use script_thread::SendableMainThreadScriptChan;
 use script_thread::{MainThreadScriptChan, MainThreadScriptMsg, RunnableWrapper};
 use script_traits::{ConstellationControlMsg, UntrustedNodeAddress};
 use script_traits::{DocumentState, MsDuration, ScriptToCompositorMsg, TimerEvent, TimerEventId};
-use script_traits::{MozBrowserEvent, ScriptMsg as ConstellationMsg, TimerEventRequest, TimerSource};
+use script_traits::{ScriptMsg as ConstellationMsg, TimerEventRequest, TimerSource};
 use std::ascii::AsciiExt;
 use std::borrow::ToOwned;
 use std::cell::Cell;
@@ -85,6 +85,8 @@ use task_source::networking::NetworkingTaskSource;
 use task_source::user_interaction::UserInteractionTaskSource;
 use time;
 use timers::{IsInterval, OneshotTimerCallback, OneshotTimerHandle, OneshotTimers, TimerCallback};
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+use tinyfiledialogs::{self, MessageBoxIcon};
 use url::Url;
 use util::geometry::{self, MAX_RECT};
 use util::str::{DOMString, HTML_SPACE_CHARACTERS};
@@ -343,6 +345,16 @@ impl Window {
     }
 }
 
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+fn display_alert_dialog(message: &str) {
+    tinyfiledialogs::message_box_ok("Alert!", message, MessageBoxIcon::Warning);
+}
+
+#[cfg(not(any(target_os = "macos", target_os = "linux")))]
+fn display_alert_dialog(_message: &str) {
+    // tinyfiledialogs not supported on Windows
+}
+
 // https://html.spec.whatwg.org/multipage/#atob
 pub fn base64_btoa(input: DOMString) -> Fallible<DOMString> {
     // "The btoa() method must throw an InvalidCharacterError exception if
@@ -425,10 +437,13 @@ impl WindowMethods for Window {
         stdout.flush().unwrap();
         stderr.flush().unwrap();
 
-        // https://developer.mozilla.org/en-US/docs/Web/Events/mozbrowsershowmodalprompt
-        let event = MozBrowserEvent::ShowModalPrompt("alert".to_owned(), "Alert".to_owned(),
-                                                     String::from(s), "".to_owned());
-        self.Document().trigger_mozbrowser_event(event);
+        let (sender, receiver) = ipc::channel().unwrap();
+        self.constellation_chan().0.send(ConstellationMsg::Alert(self.pipeline(), s.to_string(), sender)).unwrap();
+
+        let should_display_alert_dialog = receiver.recv().unwrap();
+        if should_display_alert_dialog {
+            display_alert_dialog(&s);
+        }
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-window-close

components/script/lib.rs

@@ -73,6 +73,8 @@ extern crate smallvec;
 #[macro_use]
 extern crate style;
 extern crate time;
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+extern crate tinyfiledialogs;
 extern crate unicase;
 extern crate url;
 #[macro_use]

components/script_traits/script_msg.rs

@@ -81,4 +81,6 @@ pub enum ScriptMsg {
     SetDocumentState(PipelineId, DocumentState),
     /// Update the pipeline Url, which can change after redirections.
     SetFinalUrl(PipelineId, Url),
+    /// Check if an alert dialog box should be presented
+    Alert(PipelineId, String, IpcSender<bool>),
 }

components/servo/Cargo.lock

@@ -16,4 +16,16 @@
         }));
         document.body.appendChild(iframe);
     });
+
+    async_test(function(t) {
+        var iframe = document.createElement("iframe");
+        iframe.mozbrowser = "true";
+        iframe.src = "mozbrowsershowmodalprompt_event_nested_iframe.html";
+        iframe.addEventListener("mozbrowsershowmodalprompt", t.step_func(e => {
+            assert_equals(e.detail.promptType, "alert");
+            assert_equals(e.detail.message, "my alert message");
+            t.done();
+        }));
+        document.body.appendChild(iframe);
+    }, "mozbrowsershowmodalprompt event from nested iframes triggering an alert");
 </script>

ports/cef/Cargo.lock

@@ -0,0 +1,5 @@
+<html>
+    <body>
+        <iframe src="mozbrowsershowmodalprompt_event_iframe.html" />
+    </body>
+</html>