Move page index logic into WelcomePagesModel

cura/UI/WelcomePagesModel.py

@@ -1,10 +1,12 @@
 # Copyright (c) 2019 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
+from collections import deque
 import os
-from typing import TYPE_CHECKING, Optional, List, Dict, Any
+from typing import TYPE_CHECKING, Optional, List, Dict, Any, Deque
 
-from PyQt5.QtCore import QUrl, Qt
+from PyQt5.QtCore import QUrl, Qt, pyqtSlot, pyqtProperty, pyqtSignal
 
+from UM.Logger import Logger
 from UM.Qt.ListModel import ListModel
 from UM.Resources import Resources
 
@@ -27,6 +29,99 @@ class WelcomePagesModel(ListModel):
 
         self._pages = []  # type: List[Dict[str, Any]]
 
+        self._current_page_index = 0
+        # Store all the previous page indices so it can go back.
+        self._previous_page_indices_stack = deque()  # type: Deque[int]
+
+    allFinished = pyqtSignal()  # emitted when all steps have been finished
+    currentPageIndexChanged = pyqtSignal()
+
+    @pyqtProperty(int, notify = currentPageIndexChanged)
+    def currentPageIndex(self) -> int:
+        return self._current_page_index
+
+    # Returns a float number in [0, 1] which indicates the current progress.
+    @pyqtProperty(float, notify = currentPageIndexChanged)
+    def currentProgress(self) -> float:
+        return self._current_page_index / len(self._items)
+
+    # Indicates if the current page is the last page.
+    @pyqtProperty(bool, notify = currentPageIndexChanged)
+    def isCurrentPageLast(self) -> bool:
+        return self._current_page_index == len(self._items) - 1
+
+    def _setCurrentPageIndex(self, page_index: int) -> None:
+        if page_index != self._current_page_index:
+            self._previous_page_indices_stack.append(self._current_page_index)
+            self._current_page_index = page_index
+            self.currentPageIndexChanged.emit()
+
+    # Goes to the next page.
+    @pyqtSlot()
+    def goToNextPage(self) -> None:
+        page_item = self._items[self._current_page_index]
+        # Check if there's a "next_page_id" assigned. If so, go to that page. Otherwise, go to the page with the
+        # current index + 1.
+        next_page_id = page_item.get("next_page_id")
+        next_page_index = self._current_page_index + 1
+        if next_page_id:
+            idx = self.getPageIndexById(next_page_id)
+            if idx is None:
+                # FIXME: If we cannot find the next page, we cannot do anything here.
+                Logger.log("e", "Cannot find page with ID [%s]", next_page_id)
+                return
+            next_page_index = idx
+
+        # If we have reached the last page, emit allFinished signal and reset.
+        if next_page_index == len(self._items):
+            self.allFinished.emit()
+            self.resetState()
+
+        # Move to the next page
+        self._setCurrentPageIndex(next_page_index)
+
+    # Goes to the previous page. If there's no previous page, do nothing.
+    @pyqtSlot()
+    def goToPreviousPage(self) -> None:
+        if len(self._previous_page_indices_stack) == 0:
+            Logger.log("i", "No previous page, do nothing")
+            return
+
+        previous_page_index = self._previous_page_indices_stack.pop()
+        self._current_page_index = previous_page_index
+        self.currentPageIndexChanged.emit()
+
+    # Sets the current page to the given page ID. If the page ID is not found, do nothing.
+    @pyqtSlot(str)
+    def goToPage(self, page_id: str) -> None:
+        page_index = self.getPageIndexById(page_id)
+        if page_index is None:
+            # FIXME: If we cannot find the next page, we cannot do anything here.
+            Logger.log("e", "Cannot find page with ID [%s]", page_index)
+            return
+
+        # Move to that page
+        self._setCurrentPageIndex(page_index)
+
+    # Resets the state of the WelcomePagesModel. This functions does the following:
+    #  - Resets current_page_index to 0
+    #  - Clears the previous page indices stack
+    @pyqtSlot()
+    def resetState(self) -> None:
+        self._current_page_index = 0
+        self._previous_page_indices_stack.clear()
+
+        self.currentPageIndexChanged.emit()
+
+    # Gets the page index with the given page ID. If the page ID doesn't exist, returns None.
+    def getPageIndexById(self, page_id: str) -> Optional[int]:
+        page_idx = None
+        for idx, page_item in enumerate(self._items):
+            if page_item["id"] == page_id:
+                page_idx = idx
+                break
+        return page_idx
+
     # Convenience function to get QUrl path to pages that's located in "resources/qml/WelcomePages".
     def _getBuiltinWelcomePagePath(self, page_filename: str) -> "QUrl":
         from cura.CuraApplication import CuraApplication
@@ -49,9 +144,11 @@ class WelcomePagesModel(ListModel):
                             })
         self._pages.append({"id": "add_network_or_local_printer",
                             "page_url": self._getBuiltinWelcomePagePath("AddNetworkOrLocalPrinterContent.qml"),
+                            "next_page_id": "machine_actions",
                             })
         self._pages.append({"id": "add_printer_by_ip",
                             "page_url": self._getBuiltinWelcomePagePath("AddPrinterByIpContent.qml"),
+                            "next_page_id": "machine_actions",
                             })
         self._pages.append({"id": "machine_actions",
                             "page_url": self._getBuiltinWelcomePagePath("FirstStartMachineActionsContent.qml"),

resources/qml/Cura.qml

@@ -77,7 +77,6 @@ UM.MainWindow
         if (CuraApplication.needToShowUserAgreement)
         {
             welcomeDialog.visible = true;
-            welcomeDialog.currentStep = 0;
         }
         else
         {

resources/qml/WelcomePages/AddNetworkOrLocalPrinterContent.qml

@@ -145,7 +145,7 @@ Item
                 const localPrinterItem = addLocalPrinterDropDown.contentItem.currentItem
                 Cura.MachineManager.addMachine(localPrinterItem.id)
 
-                base.goToPage("machine_actions")
+                base.showNextPage()
             }
         }
     }

resources/qml/WelcomePages/AddPrinterByIpContent.qml

@@ -247,7 +247,7 @@ Item
         text: catalog.i18nc("@button", "Cancel")
         width: UM.Theme.getSize("action_button").width
         fixedWidthMode: true
-        onClicked: base.goToPage("add_network_or_local_printer")
+        onClicked: base.showPreviousPage()
     }
 
     Cura.PrimaryButton

resources/qml/WelcomePages/FirstStartMachineActionsContent.qml

@@ -33,6 +33,7 @@ Item
     {
         if (visible)
         {
+            // Reset the action to start from the beginning when it is shown.
             currentActionIndex = 0
             if (!hasActions)
             {
@@ -48,7 +49,7 @@ Item
         anchors.topMargin: UM.Theme.getSize("welcome_pages_default_margin").height
         anchors.horizontalCenter: parent.horizontalCenter
         horizontalAlignment: Text.AlignHCenter
-        text: currentActionItem.title
+        text: currentActionItem == null ? "" : currentActionItem.title
         color: UM.Theme.getColor("primary_button")
         font: UM.Theme.getFont("large_bold")
         renderType: Text.NativeRendering

resources/qml/WelcomePages/StepPanel.qml

@@ -21,70 +21,30 @@ Item
     property int stepBarHeight: 12
     property int contentMargins: 1
 
-    property int currentStep: 0
-    property int totalStepCount: (model == null) ? 0 : model.count
-    property real progressValue: (totalStepCount == 0) ? 0 : (currentStep / totalStepCount)
-
-    property var currentItem: (model == null) ? null : model.getItem(currentStep)
+    property var currentItem: (model == null) ? null : model.getItem(model.currentPageIndex)
     property var model: null
 
+    property var progressValue: model == null ? 0 : model.currentProgress
+    property string pageUrl: currentItem == null ? null : currentItem.page_url
+
     signal showNextPage()
     signal showPreviousPage()
-    signal passLastPage()  // Emitted when there is no more page to show
     signal goToPage(string page_id)  // Go to a specific page by the given page_id.
 
-    onShowNextPage:
-    {
-        if (currentStep < totalStepCount - 1)
-        {
-            currentStep++
-        }
-        else
-        {
-            passLastPage()
-        }
-    }
-
-    onShowPreviousPage:
-    {
-        if (currentStep > 0)
-        {
-            currentStep--
-        }
-    }
-
-    onGoToPage:
-    {
-        // find the page index
-        var page_index = -1
-        for (var i = 0; i < base.model.count; i++)
-        {
-            const item = base.model.getItem(i)
-            if (item.id == page_id)
-            {
-                page_index = i
-                break
-            }
-        }
-        if (page_index >= 0)
-        {
-            currentStep = page_index
-        }
-    }
+    // Call the corresponding functions in the model
+    onShowNextPage: model.goToNextPage()
+    onShowPreviousPage: model.goToPreviousPage()
+    onGoToPage: model.goToPage(page_id)
 
     onVisibleChanged:
     {
         if (visible)
         {
-            base.currentStep = 0
-            base.currentItem = base.model.getItem(base.currentStep)
+            model.resetState()
         }
     }
 
-    onModelChanged:
-    {
-        base.currentStep = 0
-    }
+    onModelChanged: model.resetState()
 
     // Panel background
     Rectangle
@@ -137,6 +97,6 @@ Item
             left: parent.left
             right: parent.right
         }
-        source: base.currentItem.page_url
+        source: base.pageUrl
     }
 }

resources/qml/WelcomePages/WelcomeDialog.qml

@@ -9,8 +9,12 @@ import UM 1.3 as UM
 import Cura 1.1 as Cura
 
 
+//
+// This is a no-frame dialog that shows the welcome process.
+//
 Window
 {
+    id: dialog
     UM.I18nCatalog { id: catalog; name: "cura" }
 
     title: catalog.i18nc("@title", "Welcome to Ultimaker Cura")
@@ -21,19 +25,18 @@ Window
     height: 600  // TODO
     color: "transparent"
 
-    property alias currentStep: stepPanel.currentStep
+    property var model: CuraApplication.getWelcomePagesModel()
 
     StepPanel
     {
         id: stepPanel
-        currentStep: 0
-        model: CuraApplication.getWelcomePagesModel()
+        model: dialog.model
     }
 
     // Close this dialog when there's no more page to show
     Connections
     {
-        target: stepPanel
-        onPassLastPage: close()
+        target: model
+        onAllFinished: close()
     }
 }