From b78b89f04f75c3b113e62179a863dca3395112ec Mon Sep 17 00:00:00 2001
From: Florian Bruhin <git@the-compiler.org>
Date: Wed, 13 Jul 2016 10:54:42 +0200
Subject: [PATCH] QtWebEngine: Implement :scroll-perc via JS

---
 qutebrowser/browser/browsertab.py             |  5 +--
 qutebrowser/browser/webengine/webenginetab.py | 12 +++++--
 qutebrowser/browser/webkit/webkittab.py       |  2 +-
 qutebrowser/javascript/scroll.js              | 34 +++++++++++++++++++
 4 files changed, 47 insertions(+), 6 deletions(-)
 create mode 100644 qutebrowser/javascript/scroll.js

diff --git a/qutebrowser/browser/browsertab.py b/qutebrowser/browser/browsertab.py
index 161e2d992..f034f4755 100644
--- a/qutebrowser/browser/browsertab.py
+++ b/qutebrowser/browser/browsertab.py
@@ -349,8 +349,9 @@ class AbstractScroller(QObject):
 
     perc_changed = pyqtSignal(int, int)
 
-    def __init__(self, parent=None):
+    def __init__(self, tab, parent=None):
         super().__init__(parent)
+        self._tab = tab
         self._widget = None
 
     def pos_px(self):
@@ -493,7 +494,7 @@ class AbstractTab(QWidget):
         objreg.register('tab', self, registry=self.registry)
 
         # self.history = AbstractHistory(self)
-        # self.scroll = AbstractScroller(parent=self)
+        # self.scroll = AbstractScroller(self, parent=self)
         # self.caret = AbstractCaret(win_id=win_id, tab=self, mode_manager=...,
         #                            parent=self)
         # self.zoom = AbstractZoom(win_id=win_id)
diff --git a/qutebrowser/browser/webengine/webenginetab.py b/qutebrowser/browser/webengine/webenginetab.py
index 91cfc1e03..b6323ad85 100644
--- a/qutebrowser/browser/webengine/webenginetab.py
+++ b/qutebrowser/browser/webengine/webenginetab.py
@@ -32,7 +32,7 @@ from PyQt5.QtWebEngineWidgets import QWebEnginePage
 
 from qutebrowser.browser import browsertab
 from qutebrowser.browser.webengine import webview
-from qutebrowser.utils import usertypes, qtutils, log
+from qutebrowser.utils import usertypes, qtutils, log, utils
 
 
 class WebEnginePrinting(browsertab.AbstractPrinting):
@@ -213,7 +213,13 @@ class WebEngineScroller(browsertab.AbstractScroller):
             return (perc_x, perc_y)
 
     def to_perc(self, x=None, y=None):
-        log.stub()
+        js_code = """
+            {scroll_js}
+            scroll_to_perc({x}, {y});
+        """.format(scroll_js=utils.read_file('javascript/scroll.js'),
+                   x='undefined' if x is None else x,
+                   y='undefined' if y is None else y)
+        self._tab.run_js_async(js_code)
 
     def to_point(self, point):
         log.stub()
@@ -303,7 +309,7 @@ class WebEngineTab(browsertab.AbstractTab):
         super().__init__(win_id)
         widget = webview.WebEngineView()
         self.history = WebEngineHistory(self)
-        self.scroll = WebEngineScroller()
+        self.scroll = WebEngineScroller(self, parent=self)
         self.caret = WebEngineCaret(win_id=win_id, mode_manager=mode_manager,
                                     tab=self, parent=self)
         self.zoom = WebEngineZoom(win_id=win_id, parent=self)
diff --git a/qutebrowser/browser/webkit/webkittab.py b/qutebrowser/browser/webkit/webkittab.py
index 09307e5e4..26a3dd663 100644
--- a/qutebrowser/browser/webkit/webkittab.py
+++ b/qutebrowser/browser/webkit/webkittab.py
@@ -499,7 +499,7 @@ class WebKitTab(browsertab.AbstractTab):
         super().__init__(win_id)
         widget = webview.WebView(win_id, self.tab_id, tab=self)
         self.history = WebKitHistory(self)
-        self.scroll = WebKitScroller(parent=self)
+        self.scroll = WebKitScroller(self, parent=self)
         self.caret = WebKitCaret(win_id=win_id, mode_manager=mode_manager,
                                  tab=self, parent=self)
         self.zoom = WebKitZoom(win_id=win_id, parent=self)
diff --git a/qutebrowser/javascript/scroll.js b/qutebrowser/javascript/scroll.js
new file mode 100644
index 000000000..59dea1dac
--- /dev/null
+++ b/qutebrowser/javascript/scroll.js
@@ -0,0 +1,34 @@
+/**
+ * Copyright 2016 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+ *
+ * This file is part of qutebrowser.
+ *
+ * qutebrowser is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * qutebrowser is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+function scroll_to_perc(x, y) {
+    var elem = document.documentElement;
+    var x_px = window.scrollX;
+    var y_px = window.scrollY;
+
+    if (x !== undefined) {
+        x_px = (elem.scrollWidth - elem.clientWidth) / 100 * x;
+    }
+
+    if (y !== undefined) {
+        y_px  = (elem.scrollHeight - elem.clientHeight) / 100 * y;
+    }
+
+    window.scroll(x_px, y_px);
+}