From 6e17a19a902c3bf96183855170ac7462fedcae83 Mon Sep 17 00:00:00 2001
From: Andreas Butti <andreas.butti@gmail.com>
Date: Sun, 2 Dec 2018 08:20:45 +0100
Subject: [PATCH] Try to disable scrolling if pen is active

---
 src/gui/Layout.cpp     | 53 ++++++++++++++++++++++++++++++++++--------
 src/gui/Layout.h       | 14 ++++-------
 src/gui/MainWindow.cpp | 12 +++++-----
 3 files changed, 54 insertions(+), 25 deletions(-)

diff --git a/src/gui/Layout.cpp b/src/gui/Layout.cpp
index 40d07167..51fe7623 100644
--- a/src/gui/Layout.cpp
+++ b/src/gui/Layout.cpp
@@ -7,20 +7,38 @@
 #include "widgets/XournalWidget.h"
 
 
-Layout::Layout(XournalView* _view,
+Layout::Layout(XournalView* view,
                GtkAdjustment* adjHorizontal,
 	           GtkAdjustment* adjVertical)
- : view(_view),
+ : view(view),
    adjHorizontal(adjHorizontal),
    adjVertical(adjVertical),
+   lastScrollHorizontal(-1),
+   lastScrollVertical(-1),
    lastWidgetWidth(0),
    layoutWidth(0),
    layoutHeight(0)
 {
 	XOJ_INIT_TYPE(Layout);
 
-	g_signal_connect(adjHorizontal, "value-changed", G_CALLBACK(adjustmentValueChanged), this);
-	g_signal_connect(adjVertical, "value-changed", G_CALLBACK(adjustmentValueChanged), this);
+	g_signal_connect(adjHorizontal, "value-changed", G_CALLBACK(
+		+[](GtkAdjustment* adjustment, Layout* layout)
+		{
+			XOJ_CHECK_TYPE_OBJ(layout, Layout);
+			layout->checkScroll(adjustment, layout->lastScrollHorizontal);
+			layout->updateCurrentPage();
+		}), this);
+
+	g_signal_connect(adjVertical, "value-changed", G_CALLBACK(
+		+[](GtkAdjustment* adjustment, Layout* layout)
+		{
+			XOJ_CHECK_TYPE_OBJ(layout, Layout);
+			layout->checkScroll(adjustment, layout->lastScrollVertical);
+			layout->updateCurrentPage();
+		}), this);
+
+	lastScrollHorizontal = gtk_adjustment_get_value(adjHorizontal);
+	lastScrollVertical = gtk_adjustment_get_value(adjVertical);
 }
 
 Layout::~Layout()
@@ -28,11 +46,26 @@ Layout::~Layout()
 	XOJ_RELEASE_TYPE(Layout);
 }
 
+void Layout::checkScroll(GtkAdjustment* adjustment, double& lastScroll)
+{
+	XOJ_CHECK_TYPE(Layout);
+
+	if (!view->shouldIgnoreTouchEvents())
+	{
+		lastScroll = gtk_adjustment_get_value(adjustment);
+		return;
+	}
+
+	gtk_adjustment_set_value(adjustment, lastScroll);
+}
+
 /**
  * Check which page should be selected
  */
 void Layout::updateCurrentPage()
 {
+	XOJ_CHECK_TYPE(Layout);
+
 	Rectangle visRect = getVisibleRect();
 
 	Control* control = this->view->getControl();
@@ -116,14 +149,10 @@ void Layout::updateCurrentPage()
 	}
 }
 
-void Layout::adjustmentValueChanged(GtkAdjustment* adjustment,
-                                    Layout* layout)
-{
-	layout->updateCurrentPage();
-}
-
 Rectangle Layout::getVisibleRect()
 {
+	XOJ_CHECK_TYPE(Layout);
+
 	return Rectangle(gtk_adjustment_get_value(adjHorizontal),
 	                 gtk_adjustment_get_value(adjVertical),
 	                 gtk_adjustment_get_page_size(adjHorizontal),
@@ -135,6 +164,8 @@ Rectangle Layout::getVisibleRect()
  */
 double Layout::getLayoutHeight()
 {
+	XOJ_CHECK_TYPE(Layout);
+
 	return layoutHeight;
 }
 
@@ -143,6 +174,8 @@ double Layout::getLayoutHeight()
  */
 double Layout::getLayoutWidth()
 {
+	XOJ_CHECK_TYPE(Layout);
+
 	return layoutWidth;
 }
 
diff --git a/src/gui/Layout.h b/src/gui/Layout.h
index c47a84f0..c87f51e0 100644
--- a/src/gui/Layout.h
+++ b/src/gui/Layout.h
@@ -84,18 +84,11 @@ public:
 	 */
 	void updateCurrentPage();
 
-public:
-	/**
-	 * Callback for a changed value of one of the adjustments of
-	 * the scrolled window. It updates the current XojPageView
-	 * via Layout::updateCurrentPage()
-	 */
-	static void adjustmentValueChanged(GtkAdjustment* adjustment,
-	                                   Layout* layout);
-
 private:
+	void checkScroll(GtkAdjustment* adjustment, double& lastScroll);
 	void setLayoutSize(int width, int height);
 
+private:
 	XOJ_TYPE_ATTRIB;
 
 	XournalView* view;
@@ -103,6 +96,9 @@ private:
 	GtkAdjustment* adjHorizontal;
 	GtkAdjustment* adjVertical;
 
+	double lastScrollHorizontal;
+	double lastScrollVertical;
+
 	/**
 	 * The last width of the widget
 	 */
diff --git a/src/gui/MainWindow.cpp b/src/gui/MainWindow.cpp
index 84515d64..e0150f2e 100644
--- a/src/gui/MainWindow.cpp
+++ b/src/gui/MainWindow.cpp
@@ -29,8 +29,8 @@ using std::cout;
 using std::endl;
 namespace bf = boost::filesystem;
 
-MainWindow::MainWindow(GladeSearchpath* gladeSearchPath, Control* control) :
-		GladeGui(gladeSearchPath, "main.glade", "mainWindow")
+MainWindow::MainWindow(GladeSearchpath* gladeSearchPath, Control* control)
+ : GladeGui(gladeSearchPath, "main.glade", "mainWindow")
 {
 	XOJ_INIT_TYPE(MainWindow);
 
@@ -61,13 +61,13 @@ MainWindow::MainWindow(GladeSearchpath* gladeSearchPath, Control* control) :
 	setSidebarVisible(control->getSettings()->isSidebarVisible());
 
 	// Window handler
-	g_signal_connect(this->window, "delete-event", (GCallback) & deleteEventCallback, this->control);
-	g_signal_connect(this->window, "window_state_event", G_CALLBACK(&windowStateEventCallback), this);
+	g_signal_connect(this->window, "delete-event", G_CALLBACK(deleteEventCallback), this->control);
+	g_signal_connect(this->window, "window_state_event", G_CALLBACK(windowStateEventCallback), this);
 
 	g_signal_connect(get("buttonCloseSidebar"), "clicked", G_CALLBACK(buttonCloseSidebarClicked), this);
 
 	// "watch over" all events
-	g_signal_connect(this->window, "key-press-event", (GCallback) & onKeyPressCallback, this);
+	g_signal_connect(this->window, "key-press-event", G_CALLBACK(onKeyPressCallback), this);
 
 	this->toolbar = new ToolMenuHandler(this->control, this, GTK_WINDOW(getWindow()));
 
@@ -97,7 +97,7 @@ MainWindow::MainWindow(GladeSearchpath* gladeSearchPath, Control* control) :
 	createToolbarAndMenu();
 
 	GtkWidget* menuViewSidebarVisible = get("menuViewSidebarVisible");
-	g_signal_connect(menuViewSidebarVisible, "toggled", (GCallback) viewShowSidebar, this);
+	g_signal_connect(menuViewSidebarVisible, "toggled", G_CALLBACK(viewShowSidebar), this);
 
 	updateScrollbarSidebarPosition();