Tests: Where a pan may start, and what stays a click

- from the background, and from a button of a node: the view pans;
- from a widget that uses the navigate button: it keeps the button, no pan;
- from outside the editor: no pan (thedmd#238);
- a right click on a button of a node: its context menu and the node's, as before;
- a pan that ends on the button it started from: no context menu.

Author: pthom

tests/CMakeLists.txt

@@ -86,6 +86,7 @@ set(_TestSources
     lifetime_tests.cpp
     link_tests.cpp
     math_tests.cpp
+    pan_tests.cpp
     popup_callback_tests.cpp
     protocol_tests.cpp
     settings_tests.cpp

tests/pan_tests.cpp

@@ -0,0 +1,133 @@
+//------------------------------------------------------------------------------
+// Where a pan with the navigate button may start: the background, a node, a
+// widget of a node which does not use that button. Not a widget which uses it,
+// nor a press outside the editor (#238). A click stays a click; the release that
+// ends a pan is not one.
+//------------------------------------------------------------------------------
+# include "harness.h"
+
+namespace {
+
+struct PanScene
+{
+    ImVec2 ButtonCenter, RightButtonCenter, OriginOnScreen;
+    bool   RightButtonHeld = false;
+    int    ButtonContextMenus = 0;  // the condition of BeginPopupContextItem() on the button
+    int    NodeContextMenus = 0;    // ed::ShowNodeContextMenu() for the node
+
+    void operator()(int frame)
+    {
+        if (frame == 0)
+            ed::SetNodePosition(1, ImVec2(100.0f, 100.0f));
+        ed::BeginNode(1);
+        ImGui::Text("Node");
+        ImGui::Button("A button", ImVec2(150.0f, 40.0f));
+        ButtonCenter = ed::CanvasToScreen((ImGui::GetItemRectMin() + ImGui::GetItemRectMax()) * 0.5f);
+        if (ImGui::IsMouseReleased(ImGuiMouseButton_Right) && ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
+            ++ButtonContextMenus;
+        ImGui::InvisibleButton("uses the navigate button", ImVec2(150.0f, 40.0f), ImGuiButtonFlags_MouseButtonRight);
+        RightButtonCenter = ed::CanvasToScreen((ImGui::GetItemRectMin() + ImGui::GetItemRectMax()) * 0.5f);
+        RightButtonHeld = RightButtonHeld || ImGui::IsItemActive();
+        ed::EndNode();
+        OriginOnScreen = ed::CanvasToScreen(ImVec2(0.0f, 0.0f));
+        ed::Suspend();
+        ed::NodeId nodeId;
+        if (ed::ShowNodeContextMenu(&nodeId) && nodeId == ed::NodeId(1))
+            ++NodeContextMenus;
+        ed::Resume();
+    }
+};
+
+// Drags with the navigate button from 'from', and returns how far the view moved.
+ImVec2 DragAndMeasure(test::Session& session, PanScene& scene, ImVec2 from, ImVec2 delta)
+{
+    const ImVec2 before = scene.OriginOnScreen;
+    session.Drag(from, from + delta, ed::Config().NavigateButtonIndex);
+    return scene.OriginOnScreen - before;
+}
+
+bool Equal(ImVec2 a, ImVec2 b) { return ImFabs(a.x - b.x) < 1.0f && ImFabs(a.y - b.y) < 1.0f; }
+
+} // namespace
+
+TEST_CASE(PanFromBackground, "interaction.pan_from_the_background", "#238", test::TestFlags_None)
+{
+    test::Storage storage;
+    test::Session session(&storage);
+    PanScene scene;
+    session.DefaultContent = std::ref(scene);
+    session.Run(3);
+
+    const ImVec2 delta(80.0f, 50.0f);
+    const ImVec2 moved = DragAndMeasure(session, scene, session.HostPos + ImVec2(700.0f, 500.0f), delta);
+    test::Check(Equal(moved, delta), "a drag from the background pans the view: moved by (%g, %g), the mouse by (%g, %g)", moved.x, moved.y, delta.x, delta.y);
+}
+
+TEST_CASE(PanFromWidget, "interaction.pan_from_a_widget_in_a_node", "#238", test::TestFlags_None)
+{
+    test::Storage storage;
+    test::Session session(&storage);
+    PanScene scene;
+    session.DefaultContent = std::ref(scene);
+    session.Run(3);
+
+    const ImVec2 delta(80.0f, 50.0f);
+    const ImVec2 moved = DragAndMeasure(session, scene, scene.ButtonCenter, delta);
+    test::Check(Equal(moved, delta), "a drag from a button of a node (which uses another mouse button) pans the view: moved by (%g, %g), the mouse by (%g, %g)", moved.x, moved.y, delta.x, delta.y);
+}
+
+TEST_CASE(NoPanFromWidgetUsingTheButton, "interaction.no_pan_from_a_widget_using_the_navigate_button", "#238", test::TestFlags_None)
+{
+    test::Storage storage;
+    test::Session session(&storage);
+    PanScene scene;
+    session.DefaultContent = std::ref(scene);
+    session.Run(3);
+
+    const ImVec2 moved = DragAndMeasure(session, scene, scene.RightButtonCenter, ImVec2(80.0f, 50.0f));
+    test::Check(Equal(moved, ImVec2(0.0f, 0.0f)), "a drag from a widget which uses the navigate button does not pan: moved by (%g, %g)", moved.x, moved.y);
+    test::Check(scene.RightButtonHeld, "the widget keeps the navigate button: it was held");
+}
+
+TEST_CASE(NoPanFromOutside, "interaction.no_pan_from_outside_the_editor", "#238", test::TestFlags_None)
+{
+    test::Storage storage;
+    test::Session session(&storage);
+    PanScene scene;
+    session.DefaultContent = std::ref(scene);
+    session.Run(3);
+
+    // Pressed right of the host window, where no window is, then dragged over the editor.
+    const ImVec2 from = session.HostPos + ImVec2(session.HostSize.x + 100.0f, 300.0f);
+    const ImVec2 moved = DragAndMeasure(session, scene, from, ImVec2(-500.0f, 0.0f));
+    test::Check(Equal(moved, ImVec2(0.0f, 0.0f)), "a drag pressed outside the editor does not pan when it enters it: moved by (%g, %g)", moved.x, moved.y);
+}
+
+TEST_CASE(RightClickOnWidget, "interaction.right_click_on_a_widget_in_a_node", "#238", test::TestFlags_None)
+{
+    test::Storage storage;
+    test::Session session(&storage);
+    PanScene scene;
+    session.DefaultContent = std::ref(scene);
+    session.Run(3);
+
+    session.Click(scene.ButtonCenter, ed::Config().ContextMenuButtonIndex);
+    test::Check(scene.ButtonContextMenus == 1, "a right click on a button of a node opens its context menu: %d times", scene.ButtonContextMenus);
+    test::Check(scene.NodeContextMenus == 1, "and the context menu of the node, as before: %d times", scene.NodeContextMenus);
+}
+
+TEST_CASE(NoClickAtTheEndOfAPan, "interaction.no_click_at_the_end_of_a_pan", "#238", test::TestFlags_None)
+{
+    test::Storage storage;
+    test::Session session(&storage);
+    PanScene scene;
+    session.DefaultContent = std::ref(scene);
+    session.Run(3);
+
+    // The view follows the mouse: the drag ends on the button it started from
+    const ImVec2 delta(80.0f, 50.0f);
+    const ImVec2 moved = DragAndMeasure(session, scene, scene.ButtonCenter, delta);
+    test::Check(Equal(moved, delta), "the drag pans the view: moved by (%g, %g)", moved.x, moved.y);
+    test::Check(scene.ButtonContextMenus == 0, "the release that ends the pan opens no context menu of the button: %d times", scene.ButtonContextMenus);
+    test::Check(scene.NodeContextMenus == 0, "nor of the node: %d times", scene.NodeContextMenus);
+}