pagination behaviour fixes + shuffling

src/mdemory-app-qt/main.go

@@ -1,13 +1,21 @@
 package main
 
-// TODO: open flashcard with many answers and switch mdem file,
-// it remains opens with the same options -> Rehide the answers.
+// iter: 1
+// [1] 2 3 4 5 6 7
+
+// 2
+// press 4
+//  1 2 3 [4] 5 6 7
+// 4 (page num) - 2
+
 
 import (
 	"fmt"
 	"os"
 	"strings"
 	"time"
+    "strconv"
+    "math/rand"
 
 	"github.com/jorenchik/mdemory/src/compiler/api"
 	"github.com/jorenchik/mdemory/src/compiler/parser"
@@ -15,10 +23,33 @@ import (
 	"github.com/therecipe/qt/widgets"
 )
 
-var hMdemScroll *widgets.QVBoxLayout
-var mdemSpacer *widgets.QSpacerItem
-var spacerInitialized bool = false
-var workingPath string = "/home/jorenchik/Code/mdemory/memorybase"
+type Page struct {
+    start int;
+    end   int;
+}
+
+type PaginationButton struct {
+    button *widgets.QToolButton;
+    pageIdx int;
+}
+
+var deckListLabel       *widgets.QLabel
+var hMdemScroll         *widgets.QVBoxLayout
+var mdemSpacer          *widgets.QSpacerItem
+var spacerInitialized    bool = false
+var workingPath          string = "/home/jorenchik/Code/mdemory/memorybase"
+var questions         [] parser.Question
+var paginationButtons []*widgets.QToolButton
+var paginationLabel     *widgets.QLabel
+
+// var currentPage = 0
+var PER_PAGE = 10
+var pages []Page
+var currentPage = -1
+var prevButton  *widgets.QToolButton
+var firstButton *widgets.QToolButton
+var lastButton  *widgets.QToolButton
+var nextButton  *widgets.QToolButton
 
 type Mdem struct {
 	wMdem           *widgets.QWidget;
@@ -147,6 +178,7 @@ func CreateMdems(questions *[]parser.Question) {
         }
     }
 
+	// destroy widgets
 	for i := range *questions {
 		question := (*questions)[i]
 		switch question.(type) {
@@ -157,7 +189,7 @@ func CreateMdems(questions *[]parser.Question) {
             answer := strings.Trim(
                 question.(parser.SingleAnswerQuestion).Answer, " \t\n",
             ) 
-			mdems[i].backLabels[0].SetText(answer)
+			mdems[i].backLabels[0].SetText(fmt.Sprintf("- %s", answer))
             if mdems[i].wBack.IsVisible() {
                 mdems[i].wBack.Hide()
             }
@@ -172,7 +204,7 @@ func CreateMdems(questions *[]parser.Question) {
 				if k < len(mdems[i].backLabels) {
 					mdems[i].backLabels[k].SetText(answer)
 				} else {
-					label := widgets.NewQLabel2(answer, nil, 0)
+					label := widgets.NewQLabel2(fmt.Sprintf("- %s", answer), nil, 0)
 					mdems[i].backLabels = append(
 						mdems[i].backLabels,
 						label,
@@ -199,6 +231,120 @@ func CreateMdems(questions *[]parser.Question) {
 	hMdemScroll.AddItem(mdemSpacer)
 }
 
+func MakePages() {
+    pages = nil
+    for i := 0; i < (len(questions) / PER_PAGE) + 1; i++ {
+        startingIndex := PER_PAGE * i 
+        amount := PER_PAGE
+        if (i == len(questions) / PER_PAGE) {
+            amount = len(questions) % PER_PAGE
+        }
+        pages = append(
+            pages,
+            Page{startingIndex, startingIndex + amount},
+        )
+    }
+}
+
+
+var PAGINATION_COUNT int = 8
+var DISTANCE int = PAGINATION_COUNT / 2 - 1
+
+func SwitchPage(pageIdx int) {
+    currentPage = pageIdx
+    for i := range(paginationButtons) {
+        paginationButtons[i].Hide()
+    }
+    l := 0
+    paginationLabel.SetText(fmt.Sprintf("Page: %d", pageIdx + 1))
+    for i := range(mdems) {
+        if mdems[i].wBack.IsVisible() {
+            mdems[i].wBack.Hide()
+            mdems[i].showButton.SetText("Show")
+        }
+
+    }
+
+    for k := -DISTANCE; k <= DISTANCE; k = k + 1 {
+        if pageIdx + k >= 0 && pageIdx + k < len(pages) {
+            button := paginationButtons[l]
+            button.SetText(fmt.Sprintf("%d", pageIdx + k + 1))
+            if pageIdx + k != pageIdx {
+                button.Show()
+            } else {
+                button.Hide()
+            }
+            l++
+        }
+    }
+
+    if pageIdx > 0 && len(pages) > 1 {
+        firstButton.Show()
+    } else {
+        firstButton.Hide()
+    }
+    if pageIdx < len(pages) - 1 && len(pages) > 1 {
+        lastButton.Show()
+    } else {
+        lastButton.Hide()
+    }
+    if len(pages) > 0 &&
+       currentPage < len(pages) - 1 {
+        nextButton.Show()
+    } else {
+        nextButton.Hide()
+    }
+    if len(pages) > 0 &&
+       currentPage >= 1 {
+        prevButton.Show()
+    } else {
+        prevButton.Hide()
+    }
+
+    page := pages[pageIdx]
+    pageSlice := questions[page.start:page.end]
+    CreateMdems(&pageSlice)
+}
+
+func OpenModelFile(
+    model *widgets.QFileSystemModel,
+    index *core.QModelIndex,
+) {
+    if model.IsDir(index) {
+        return
+    }
+    filePath := model.FilePath(index)
+    fileContents, err := os.ReadFile(filePath)
+    if err != nil {
+        widgets.QMessageBox_Critical(
+            nil,
+            "Compilation error",
+            err.Error(),
+            widgets.QMessageBox__Ok,
+            widgets.QMessageBox__Ok,
+        )
+        return
+    }
+    deckListLabel.SetText(fmt.Sprintf("Mdem: %s", filePath))
+    start := time.Now().UnixMicro()
+    questions, err = api.Compile(string(fileContents))
+    if err != nil {
+        widgets.QMessageBox_Critical(
+            nil,
+            "Compilation error",
+            err.Error(),
+            widgets.QMessageBox__Ok,
+            widgets.QMessageBox__Ok,
+        )
+        return
+    }
+    duration := float32(time.Now().UnixMicro()-start) / 1000
+    fmt.Printf("Compilation took %.3fms", duration)
+
+    MakePages()
+    SwitchPage(0)
+}
+
 func main() {
 	// InitApp
 	app := widgets.NewQApplication(len(os.Args), os.Args)
@@ -224,41 +370,11 @@ func main() {
 	mdemList.HideColumn(1)
 	mdemList.HideColumn(2)
 	mdemList.HideColumn(3)
-	mdemList.ConnectDoubleClicked(func(index *core.QModelIndex) {
-		if model.IsDir(index) {
-			return
-		}
-		filePath := model.FilePath(index)
-		fileContents, err := os.ReadFile(filePath)
-		if err != nil {
-			widgets.QMessageBox_Critical(
-				nil,
-				"Compilation error",
-				err.Error(),
-				widgets.QMessageBox__Ok,
-				widgets.QMessageBox__Ok,
-			)
-			return
-		}
-		start := time.Now().UnixMicro()
-		questions, err := api.Compile(string(fileContents))
-		if err != nil {
-			widgets.QMessageBox_Critical(
-				nil,
-				"Compilation error",
-				err.Error(),
-				widgets.QMessageBox__Ok,
-				widgets.QMessageBox__Ok,
-			)
-			return
-		}
-		duration := float32(time.Now().UnixMicro()-start) / 1000
-		fmt.Printf("Compilation took %.3fms", duration)
-        
-        // Take a slice (mock pagination for now)
-        questions = questions[0:10]
-		CreateMdems(&questions)
-	})
+	mdemList.ConnectDoubleClicked(
+        func(index *core.QModelIndex) {
+            OpenModelFile(model, index)
+        },
+    )
 
 	deckLabel := widgets.NewQLabel2("Decks", nil, 0)
 	deckList := widgets.NewQListView(nil)
@@ -272,7 +388,7 @@ func main() {
 
 	top := widgets.NewQWidget(nil, 0)
 	hTop := widgets.NewQHBoxLayout()
-	deckListLabel := widgets.NewQLabel2("Mdem: file.mdem", nil, 0)
+	deckListLabel = widgets.NewQLabel(nil, 0)
 	top.SetLayout(hTop)
 	rightLayout.AddWidget(top, 0, 0)
 
@@ -286,6 +402,15 @@ func main() {
 	hTop.AddWidget(practice, 0, 0)
 	refresh.SetText("Refresh")
 	shuffle.SetText("Shuffle")
+    shuffle.ConnectClicked(
+        func(checked bool) {
+            for i := range questions {
+                j := rand.Intn(i + 1)
+                questions[i], questions[j] = questions[j], questions[i]
+            }
+            SwitchPage(0)
+        },
+    )
 	practice.SetText("Practice")
 
 	mdemScroll := widgets.NewQScrollArea(nil)
@@ -304,26 +429,77 @@ func main() {
         hMdemScroll.AddWidget(mdem.wMdem, 0, 0)
 	}
 
+	// CreateMdems
 	rightLayout.AddWidget(mdemScroll, 1, 0)
-	// Pagination
+
+	// MakePagination
 	pagination := widgets.NewQWidget(nil, 0)
 	hPagination := widgets.NewQHBoxLayout()
 	pagination.SetLayout(hPagination)
 
-	// TEMP: mock pagination
-	prevButton := widgets.NewQToolButton(nil)
+	firstButton = widgets.NewQToolButton(nil)
+	firstButton.SetText("<<")
+	hPagination.AddWidget(firstButton, 0, 0)
+    firstButton.Hide()
+    firstButton.ConnectClicked(func(checked bool) {
+        if len(pages) > 0 {
+            SwitchPage(0)
+        }
+    })
+
+	prevButton = widgets.NewQToolButton(nil)
 	prevButton.SetText("<")
 	hPagination.AddWidget(prevButton, 0, 0)
-	for i := 0; i < 5; i++ {
-		button := widgets.NewQToolButton(nil)
-		button.SetText(fmt.Sprintf("%d", i+1))
-		hPagination.AddWidget(button, 0, 0)
+    prevButton.Hide()
+    prevButton.ConnectClicked(func(checked bool) {
+        if len(pages) > 0 {
+            SwitchPage(currentPage - 1)
+        }
+    })
+
+	for i := 0; i < PAGINATION_COUNT; i++ {
+		elButton := widgets.NewQToolButton(nil)
+		elButton.SetText(fmt.Sprintf("%d", i+1))
+		hPagination.AddWidget(elButton, 0, 0)
+        elButton.Hide()
+        elButton.ConnectClicked(func(checked bool) {
+            pageNum, err := strconv.ParseInt(elButton.Text(), 10, 64)
+            _ = err
+            pageIdx := int(pageNum) - 1
+            if (pageIdx < len(pages)) {
+                SwitchPage(pageIdx)
+            }
+        })
+        paginationButtons = append(
+            paginationButtons,
+            elButton,
+        )
 	}
-	nextButton := widgets.NewQToolButton(nil)
+    
+	nextButton = widgets.NewQToolButton(nil)
 	nextButton.SetText(">")
 	hPagination.AddWidget(nextButton, 0, 0)
+    nextButton.Hide()
+    nextButton.ConnectClicked(func(checked bool) {
+        if len(pages) > 0 {
+            SwitchPage(currentPage + 1)
+        }
+    })
+
+	lastButton = widgets.NewQToolButton(nil)
+	lastButton.SetText(">>")
+	hPagination.AddWidget(lastButton, 0, 0)
+    lastButton.Hide()
+    lastButton.ConnectClicked(func(checked bool) {
+        if len(pages) > 0 {
+            SwitchPage(len(pages) - 1)
+        }
+    })
 
 	hPagination.AddStretch(1)
+    paginationLabel = widgets.NewQLabel(nil, 0)
+    hPagination.AddWidget(paginationLabel, 0, 0)
+
 	rightLayout.AddWidget(pagination, 0, 0)
 
 	hSplitter.AddWidget(leftWidget)