Auto merge of #14738 - Wafflespeanut:keypress, r=jdm

Properly dispatch keypress event

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This was an attempt to fix #14659. It turned out that the problem wasn't what I thought it was. So, I didn't fix that. On the brighter side, this fixes two related issues.

- Previously, we were unable to launch `keypress` events from `input` and `textarea` elements, because [we'd been cancelling](https://github.com/servo/servo/blob/1327ebd52f53f5f6637a12fab6cf0cad0aa0be6f/components/script/dom/htmlinputelement.rs#L1120-L1124) the key events, so that they don't trigger window navigation - #8400). I've introduced an enum to represent an additional state to an event's cancellation.
- [According to the spec](https://w3c.github.io/uievents/#keypress-event-order), `keypress` (if available) should be dispatched immediately after `keydown`, and it should be followed by `input`. Canceling `keypress` should also cancel `input`. But, we'd been dispatching `input` before `keypress`. We now dispatch `input` once the `keypress` event is on the respective elements.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

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- [x] These changes do not require tests because it's a refactor?

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r? @jdm or anyone interested

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1 files changed, 15 insertions, 14 deletions

diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index eb344ef0a79..d133efd5e14 100755
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -1105,28 +1105,29 @@ impl VirtualMethods for HTMLInputElement {
                         DispatchInput => {
                             self.value_changed.set(true);
                             self.update_placeholder_shown_state();
-
-                            if event.IsTrusted() {
-                                let window = window_from_node(self);
-                                let _ = window.user_interaction_task_source().queue_event(
-                                    &self.upcast(),
-                                    atom!("input"),
-                                    EventBubbles::Bubbles,
-                                    EventCancelable::NotCancelable,
-                                    &window);
-                            }
-
                             self.upcast::<Node>().dirty(NodeDamage::OtherNodeDamage);
-                            event.PreventDefault();
+                            event.mark_as_handled();
                         }
                         RedrawSelection => {
                             self.upcast::<Node>().dirty(NodeDamage::OtherNodeDamage);
-                            event.PreventDefault();
+                            event.mark_as_handled();
                         }
                         Nothing => (),
                     }
                 }
-        }
+        } else if event.type_() == atom!("keypress") && !event.DefaultPrevented() &&
+            (self.input_type.get() == InputType::InputText ||
+             self.input_type.get() == InputType::InputPassword) {
+                if event.IsTrusted() {
+                    let window = window_from_node(self);
+                    let _ = window.user_interaction_task_source()
+                                  .queue_event(&self.upcast(),
+                                               atom!("input"),
+                                               EventBubbles::Bubbles,
+                                               EventCancelable::NotCancelable,
+                                               &window);
+                }
+            }
     }
 }