Bug 1828295 part 3: Add tests for GetCaretRect. r=morgan

This required exposing GetCaretRect via XPCOM.

Differential Revision: https://phabricator.services.mozilla.com/D179346

accessible/interfaces/nsIAccessibleText.idl

@@ -37,6 +37,8 @@ interface nsIAccessibleText : nsISupports
    */
   attribute long caretOffset;
 
+  void getCaretRect(out long x, out long y, out long width, out long height);
+
   readonly attribute long characterCount;
   readonly attribute long selectionCount;
 

accessible/tests/browser/bounds/browser.ini

@@ -10,6 +10,7 @@ prefs =
   javascript.options.asyncstack_capture_debuggee_only=false
 
 [browser_accessible_moved.js]
+[browser_caret_rect.js]
 [browser_position.js]
 [browser_test_resolution.js]
 skip-if = os == 'win' # bug 1372296

accessible/tests/browser/bounds/browser_caret_rect.js

@@ -0,0 +1,140 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+async function getCaretRect(browser, id) {
+  // The caret rect can only be queried on LocalAccessible. On Windows, we do
+  // send it across processes with caret events, but this currently can't be
+  // queried outside of the event, nor with XPCOM.
+  const [x, y, w, h] = await invokeContentTask(browser, [id], contentId => {
+    const node = content.document.getElementById(contentId);
+    const contentAcc = content.CommonUtils.accService.getAccessibleFor(node);
+    contentAcc.QueryInterface(Ci.nsIAccessibleText);
+    const caretX = {};
+    const caretY = {};
+    const caretW = {};
+    const caretH = {};
+    contentAcc.getCaretRect(caretX, caretY, caretW, caretH);
+    return [caretX.value, caretY.value, caretW.value, caretH.value];
+  });
+  info(`Caret bounds: ${x}, ${y}, ${w}, ${h}`);
+  return [x, y, w, h];
+}
+
+async function testCaretRect(browser, docAcc, id, offset) {
+  const acc = findAccessibleChildByID(docAcc, id, [nsIAccessibleText]);
+  is(acc.caretOffset, offset, `Caret at offset ${offset}`);
+  const charX = {};
+  const charY = {};
+  const charW = {};
+  const charH = {};
+  const atEnd = offset == acc.characterCount;
+  const empty = offset == 0 && atEnd;
+  const queryOffset = atEnd && !empty ? offset - 1 : offset;
+  acc.getCharacterExtents(
+    queryOffset,
+    charX,
+    charY,
+    charW,
+    charH,
+    COORDTYPE_SCREEN_RELATIVE
+  );
+  info(
+    `Character ${queryOffset} bounds: ${charX.value}, ${charY.value}, ${charW.value}, ${charH.value}`
+  );
+  const [caretX, caretY, caretW, caretH] = await getCaretRect(browser, id);
+  if (atEnd) {
+    ok(caretX > charX.value, "Caret x after last character x");
+  } else {
+    is(caretX, charX.value, "Caret x same as character x");
+  }
+  is(caretY, charY.value, "Caret y same as character y");
+  is(caretW, 1, "Caret width is 1");
+  if (!empty) {
+    is(caretH, charH.value, "Caret height same as character height");
+  }
+}
+
+function getAccBounds(acc) {
+  const x = {};
+  const y = {};
+  const w = {};
+  const h = {};
+  acc.getBounds(x, y, w, h);
+  return [x.value, y.value, w.value, h.value];
+}
+
+/**
+ * Test the caret rect in content documents.
+ */
+addAccessibleTask(
+  `
+<input id="input" value="ab">
+<input id="emptyInput">
+  `,
+  async function (browser, docAcc) {
+    async function runTests() {
+      const input = findAccessibleChildByID(docAcc, "input", [
+        nsIAccessibleText,
+      ]);
+      info("Focusing input");
+      let caretMoved = waitForEvent(EVENT_TEXT_CARET_MOVED, input);
+      input.takeFocus();
+      await caretMoved;
+      await testCaretRect(browser, docAcc, "input", 0);
+      info("Setting caretOffset to 1");
+      caretMoved = waitForEvent(EVENT_TEXT_CARET_MOVED, input);
+      input.caretOffset = 1;
+      await caretMoved;
+      await testCaretRect(browser, docAcc, "input", 1);
+      info("Setting caretOffset to 2");
+      caretMoved = waitForEvent(EVENT_TEXT_CARET_MOVED, input);
+      input.caretOffset = 2;
+      await caretMoved;
+      await testCaretRect(browser, docAcc, "input", 2);
+      info("Resetting caretOffset to 0");
+      input.caretOffset = 0;
+
+      const emptyInput = findAccessibleChildByID(docAcc, "emptyInput", [
+        nsIAccessibleText,
+      ]);
+      info("Focusing emptyInput");
+      caretMoved = waitForEvent(EVENT_TEXT_CARET_MOVED, emptyInput);
+      emptyInput.takeFocus();
+      await caretMoved;
+      await testCaretRect(browser, docAcc, "emptyInput", 0);
+    }
+
+    await runTests();
+
+    // Check that the caret rect is correct when the title bar is shown.
+    if (LINUX || Services.env.get("MOZ_HEADLESS")) {
+      // Disabling tabs in title bar doesn't change the bounds on Linux or in
+      // headless mode.
+      info("Skipping title bar tests");
+      return;
+    }
+    const [, origDocY] = getAccBounds(docAcc);
+    info("Showing title bar");
+    let titleBarChanged = BrowserTestUtils.waitForMutationCondition(
+      document.documentElement,
+      { attributes: true, attributeFilter: ["tabsintitlebar"] },
+      () => !document.documentElement.hasAttribute("tabsintitlebar")
+    );
+    await SpecialPowers.pushPrefEnv({
+      set: [["browser.tabs.inTitlebar", false]],
+    });
+    await titleBarChanged;
+    const [, newDocY] = getAccBounds(docAcc);
+    Assert.greater(
+      newDocY,
+      origDocY,
+      "Doc has larger y after title bar change"
+    );
+    await runTests();
+    await SpecialPowers.popPrefEnv();
+  },
+  { chrome: true, topLevel: true }
+);

accessible/xpcom/xpcAccessibleHyperText.cpp

@@ -246,6 +246,28 @@ xpcAccessibleHyperText::SetCaretOffset(int32_t aCaretOffset) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+xpcAccessibleHyperText::GetCaretRect(int32_t* aX, int32_t* aY, int32_t* aWidth,
+                                     int32_t* aHeight) {
+  NS_ENSURE_ARG_POINTER(aX);
+  NS_ENSURE_ARG_POINTER(aY);
+  NS_ENSURE_ARG_POINTER(aWidth);
+  NS_ENSURE_ARG_POINTER(aHeight);
+  *aX = *aY = *aWidth = *aHeight;
+
+  if (!mIntl) {
+    return NS_ERROR_FAILURE;
+  }
+  if (mIntl->IsRemote()) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  nsIWidget* widget;
+  LayoutDeviceIntRect rect = IntlLocal()->GetCaretRect(&widget);
+  rect.GetRect(aX, aY, aWidth, aHeight);
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 xpcAccessibleHyperText::GetSelectionCount(int32_t* aSelectionCount) {
   NS_ENSURE_ARG_POINTER(aSelectionCount);