I am learning how to access SQLite without the use of Swift Data. I have a function that tests to see if a table exists and it works. The problem is that I do not understand why it works. It is my understanding that the SELECT statement returns a 0 if the table does not exist and 1 if it does. But the API step statement returns 101 (SQLITE_Done) if the table does not exist. But if the table does exist it does not return 101. Per the SQLite documentation it would appear that 101 means the operation has completed. What am I missing here and is there a way to capture the underlying SQLite 0 or 1 which would allow me to test for that? Below is my function.
func doesTableExist(db: OpaquePointer?) -> Bool {
var tableExists: Bool = true
let testForTable = """
SELECT name FROM sqlite_master
WHERE type='table'
AND name='Contact';
"""
var testForTablePtr: OpaquePointer?
if sqlite3_prepare_v2(db, testForTable, -1, &testForTablePtr, nil) == SQLITE_OK {
if sqlite3_step(testForTablePtr) == SQLITE_DONE {
tableExists = false
}
} else {
print("unable to compile sql statement testing to see if table exists")
}
return tableExists
}
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I have an SQLite table that holds a fund name, as a string, a time stamp, as an iso8601 string, and a close, as a double. SQLite appears to call strings text and a double a real. In the function below, I query this table with a select statement to return the last year of data based on the latest date in the table. To get the latest date I have a separate function that finds the latest date, converts if from a string to a date, subtracts 1 year from the date then converts it back to an iso8601 date string. It is this date string that is being passed into the function below as the variable startingDate. The function below works just fine and is relatively fast. What I am trying to determine is there a way to modify the select statement in the function below such that it does everything and I will no longer have to separately calculate the starting date and pass it in?
func QuerySQLiteData(db: OpaquePointer?, fundName: String, startingDate: String) -> [TradingDay] {
var queryResults: [TradingDay] = []
let timeStampFormatter = ISO8601DateFormatter()
let queryTradingDaysStatement = """
Select
FundName,
TimeStamp,
Close
FROM
TradingDays
WHERE
FundName = '\(fundName)'
AND
TimeStamp >= '\(startingDate)'
ORDER By
TimeStamp ASC
;
"""
var queryTradingDaysCPtr: OpaquePointer?
var tradingDay: TradingDay = TradingDay(fundName: "", timeStamp: Date(), close: 0.0)
if sqlite3_prepare_v2(db, queryTradingDaysStatement, -1, &queryTradingDaysCPtr, nil) == SQLITE_OK {
while (sqlite3_step(queryTradingDaysCPtr) == SQLITE_ROW) {
let fundName = sqlite3_column_text(queryTradingDaysCPtr, 0)
let timeStamp = sqlite3_column_text(queryTradingDaysCPtr, 1)
let close = sqlite3_column_double(queryTradingDaysCPtr, 2)
let fundNameAsString = String(cString: fundName!)
let timeStampAsString = String(cString: timeStamp!)
let timeStampAsDate = timeStampFormatter.date(from: timeStampAsString)!
tradingDay.fundName = fundNameAsString
tradingDay.timeStamp = timeStampAsDate
tradingDay.close = close
queryResults.append(tradingDay)
} // end while loop
} else {
let errorMessage = String(cString: sqlite3_errmsg(db))
print("\nQuery is not prepared \(errorMessage)")
}
sqlite3_finalize(queryTradingDaysCPtr)
return queryResults
}
I have a function that queries an SQLite database and returns names, dates and values. In SQLite the dates are in Julian format. I convert the dates in the SQLite query to a date time string which give me "2022-08-01 00:00:00". I want to display this date as the date string "Aug 1, 2022". The only way I have been able to achieve this is to convert the first date string to a date via a date formatter then convert this date to the desired date string via a second date formatter. Is there a more direct way to do this?
func AccessSQLiteDB(db: OpaquePointer?) {
let queryTradingDaysStatement = """
WITH
TempTable1
AS
(
SELECT
max(TimeStamp) - 365.25 as StartingDate
FROM
TradingDays
WHERE
FundName = 'Fund1'
),
TempTable2
AS
(
SELECT
main.FundName,
datetime(main.TimeStamp) as SQLDateString,
main.Close
FROM
TradingDays main, TempTable1 as temp
WHERE
main.FundName = 'Fund1'
AND
main.TimeStamp >= temp.StartingDate
)
SELECT
FundName,
SQLDateString,
Close
FROM
TempTable2
ORDER By
SQLDateString ASC
;
"""
let sqlDateStringFormatter = DateFormatter()
sqlDateStringFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
sqlDateStringFormatter.timeZone = .gmt
var queryTradingDaysCPtr: OpaquePointer?
if sqlite3_prepare_v2(db, queryTradingDaysStatement, -1, &queryTradingDaysCPtr, nil) == SQLITE_OK {
while (sqlite3_step(queryTradingDaysCPtr) == SQLITE_ROW) {
let fundName = sqlite3_column_text(queryTradingDaysCPtr, 0)
let timeStamp = sqlite3_column_text(queryTradingDaysCPtr, 1)
let close = sqlite3_column_double(queryTradingDaysCPtr, 2)
let fundNameAsString = String(cString: fundName!)
let timeStampAsString = String(cString: timeStamp!)
print(timeStampAsString) // returns this format 2022-08-01 00:00:00
let timeStampAsDate: Date = sqlDateStringFormatter.date(from: timeStampAsString)!
print("\(timeStampAsDate)") // returns this format 2022-08-01 00:00:00 +0000
let mediumDataFormatter = DateFormatter()
mediumDataFormatter.dateStyle = .medium
mediumDataFormatter.timeZone = .gmt
let dateString = mediumDataFormatter.string(from: timeStampAsDate)
print(dateString) // returns this format Aug 1, 2022
let closeAsString = String(format: "$%.2f", close)
print(fundNameAsString + " - " + dateString + " - " + closeAsString)
} // end while loop
} else {
let errorMessage = String(cString: sqlite3_errmsg(db))
print("\nQuery is not prepared \(errorMessage)")
}
sqlite3_finalize(queryTradingDaysCPtr)
}
I am learning SQLite queries. I use prepare statement and one or more calls to a step statement. The prepare statement knows the pointer to the database, the UFT8 select statement and the name of the pointer which will point to the complied SQL select statement. The first step call runs the compiled select statement and if data is returned, the first row is made available via column calls. It seems logical to me that the select statement returns all matching rows but if the first step statement only has access to the first row of data, the balance of matching rows must be stored somewhere. Is this the case and if so where are the query results stored? Or is does this work in some other manner?
I have a program that displays data in a table in the main view. It gets this data by running a C API Select statement. On the main view there is also a button which allows me to change the sort order to descending. To do so, this button calls the same function initially called to display data but with a different order by string for the Select statement. Selecting the button causes the data to be displayed in descending order and it is very fast. Unfortunately selecting the button also causes a warning to be displayed in Xcode "Application performed a reentrant operation in its NSTableView delegate". I do not understand what to do to resolve the issue. Any assistance will be appreciated. Below is the Context View and the View Model. The QueryDatabase function called in the view model is just the C api calls including Prepare, Step in a while loop and Finalize. If it would be helpful I can add it.
// Main View:
struct ContentView: View {
@ObservedObject var vm: SQLiteViewModel = SQLiteViewModel()
var body: some View {
if vm.loadingData == true {
ProgressView()
.task {
vm.GetSQLData(fundName: "Fund1", numYears: 1, sortOrder: "main.TimeStamp ASC")
}
} else {
HStack {
Spacer()
.frame(width: 135, height: 200, alignment: .center)
Table(vm.fundData) {
TableColumn("Fund") { record in
Text(record.fundName)
.frame(width: 60, height: 15, alignment: .center)
}
.width(60)
TableColumn("Date") { record in
Text(sqlDateFormatter.string(from: record.timeStamp))
.frame(width: 120, height: 15, alignment: .center)
}
.width(120)
TableColumn("Close") { record in
Text(String(format: "$%.2f", record.close))
.frame(width: 65, height: 15, alignment: .trailing)
}
.width(65)
} // end table
.font(.system(size: 14, weight: .regular, design: .monospaced))
.frame(width: 330, height: 565, alignment: .center)
Spacer()
.frame(width: 30, height: 30, alignment: .center)
VStack {
Button(action: {
vm.GetSQLData(fundName: "Fund1", numYears: 1, sortOrder: "main.TimeStamp DESC")
}) {
Text("Date Descending")
} // end button
.frame(width: 140)
} // end v stack
.font(.system(size: 12, weight: .regular, design: .monospaced))
} // end horizontal stack
.frame(width: 600, height: 600, alignment: .center)
} // end else statement
} // end view
}
// View Model:
class SQLiteViewModel: ObservableObject {
var db: OpaquePointer?
@Published var fundData: [TradingDay] = []
@Published var loadingData: Bool = true
init() {
db = OpenDatabase()
}
func GetSQLData(fundName: String, numYears: Int, sortOrder: String) {
DispatchQueue.main.async {
self.fundData = QueryDatabase(db: self.db, fundName: fundName, numYears: numYears, sortOrder: sortOrder)
self.loadingData = false
}
}
}
I am creating my own NSTableView for macOS. I can display formatted data and provide scrolling by embedding it in a ScrollView. When the table is displayed there is a horizontal gap between adjacent cells. The same gap occurs between the ScrollView header cells. I do not know how to. solve this problem. There is one other issue, I do not know how to set the vertical height of the ScrollView header cells. I would like to make them taller. Below is my code along with the test data.
struct ClosingValue: Identifiable {
var id: UUID
var name: String
var date: String
var close: Float
static var closingValues = [
ClosingValue(id: UUID(), name: "Stock1", date: "Nov 01, 2009", close: 1.10),
ClosingValue(id: UUID(), name: "Stock1", date: "Nov 02, 2009", close: 2.10),
ClosingValue(id: UUID(), name: "Stock1", date: "Nov 03, 2009", close: 3.10),
ClosingValue(id: UUID(), name: "Stock1", date: "Nov 04, 2009", close: 4.10),
ClosingValue(id: UUID(), name: "Stock1", date: "Nov 05, 2009", close: 5.10)
]
}
struct BetterTableView: NSViewRepresentable {
class Coordinator: NSObject, NSTableViewDelegate, NSTableViewDataSource {
@State var closingValues: [ClosingValue] = ClosingValue.closingValues
func numberOfRows(in tableView: NSTableView) -> Int {
closingValues.count
}
func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
var nsView = NSView()
let tableColumnWidth: CGFloat = 135
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .center
let attributes1: [NSAttributedString.Key: Any] = [
.foregroundColor: NSColor.blue,
.paragraphStyle: paragraphStyle,
.font: NSFont(name: "Arial", size: 14.0) as Any
]
switch tableColumn {
case tableView.tableColumns[0]:
tableColumn?.width = tableColumnWidth
let attributedString = NSAttributedString(string: closingValues[row].name, attributes: attributes1)
let tempNSView = NSTextField()
tempNSView.backgroundColor = NSColor.white
tempNSView.isBordered = true
tempNSView.isEditable = false
tempNSView.attributedStringValue = attributedString
nsView = tempNSView
case tableView.tableColumns[1]:
tableColumn?.width = tableColumnWidth
let attributedString = NSAttributedString(string: closingValues[row].date, attributes: attributes1)
let tempNSView = NSTextField()
tempNSView.backgroundColor = NSColor.white
tempNSView.isBordered = true
tempNSView.isEditable = false
tempNSView.attributedStringValue = attributedString
nsView = tempNSView
case tableView.tableColumns[2]:
tableColumn?.width = tableColumnWidth
let closeAsString = String(format: "$%.2f", closingValues[row].close)
let attributedString = NSAttributedString(string: closeAsString, attributes: attributes1)
let tempNSView = NSTextField()
tempNSView.backgroundColor = NSColor.white
tempNSView.isBordered = true
tempNSView.isEditable = false
tempNSView.attributedStringValue = attributedString
nsView = tempNSView
default:
print("problem in table view switch statement")
}
return nsView
}
}
func makeCoordinator() -> Coordinator {
Coordinator()
}
func makeNSView(context: Context) -> NSScrollView {
let tableView = NSTableView()
tableView.delegate = context.coordinator
tableView.dataSource = context.coordinator
tableView.addTableColumn(NSTableColumn())
tableView.addTableColumn(NSTableColumn())
tableView.addTableColumn(NSTableColumn())
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .center
let attributes: [NSAttributedString.Key: Any] = [
.foregroundColor: NSColor.black,
.paragraphStyle: paragraphStyle,
.font: NSFont.systemFont(ofSize: 14)
]
let column0AttributedString = NSAttributedString(string: "Stock", attributes: attributes)
let column0Header = tableView.tableColumns[0]
column0Header.headerCell.drawsBackground = true
column0Header.headerCell.backgroundColor = NSColor.systemMint
column0Header.headerCell.alignment = .center
column0Header.headerCell.attributedStringValue = column0AttributedString
let column1AttributedString = NSAttributedString(string: "Date", attributes: attributes)
let column1Header = tableView.tableColumns[1]
column1Header.headerCell.drawsBackground = true
column1Header.headerCell.backgroundColor = NSColor.systemMint
column1Header.headerCell.alignment = .center
column1Header.headerCell.attributedStringValue = column1AttributedString
let column2AttributedString = NSAttributedString(string: "Closing Value", attributes: attributes)
let column2Header = tableView.tableColumns[2]
column2Header.headerCell.drawsBackground = true
column2Header.headerCell.backgroundColor = NSColor.systemMint
column2Header.headerCell.alignment = .center
column2Header.headerCell.attributedStringValue = column2AttributedString
let scrollView = NSScrollView()
scrollView.documentView = tableView
return scrollView
}
func updateNSView(_ nsView: NSScrollView, context: Context) {
let tableView = (nsView.documentView as! NSTableView)
// work on this section
}
}
I have code that displays an NSTableView. I have the functionality I want but am having problems with the formatting. In the makeNSView function I can set the header cell text, background color and alignment. What I have been unable to determine is how to add what I would term padding to the header cell background color such that it is taller, i.e. extends further above and below the text. As a secondary issue, I would like to be able to control the border widths of the table cells i.e. the NSViews, such that they appear all the same. Right now, adjacent cell edges have double width borders and non adjacent cell edges have single width borders. Below are the displayed results and code.
struct BetterTableView: NSViewRepresentable {
func makeCoordinator() -> Coordinator {
Coordinator()
}
class Coordinator: NSObject, NSTableViewDelegate, NSTableViewDataSource {
var dateSorting: String = "ASC"
var closingSorting: String = "ASC"
var closingValues: [ClosingValue] = []
override init() {
super.init()
self.closingValues = GetValues()
}
func tableView(_ tableView: NSTableView, mouseDownInHeaderOf tableColumn: NSTableColumn) {
switch tableColumn.title {
case "Date":
if dateSorting == "ASC" {
closingValues.sort {
$0.date > $1.date
}
dateSorting = "DESC"
} else {
closingValues.sort {
$0.date < $1.date
}
dateSorting = "ASC"
}
case "Closing":
if closingSorting == "ASC" {
closingValues.sort {
$0.date > $1.date
}
closingSorting = "DESC"
} else {
closingValues.sort {
$0.date < $1.date
}
closingSorting = "ASC"
}
default:
print("default")
}
tableView.reloadData()
tableView.scrollRowToVisible(0)
}
func numberOfRows(in tableView: NSTableView) -> Int {
closingValues.count
}
func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
var nsView = NSView()
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .center
let attributes1: [NSAttributedString.Key: Any] = [
.foregroundColor: NSColor.blue,
.paragraphStyle: paragraphStyle,
.font: NSFont(name: "Arial", size: 14.0) as Any
]
var attributedString = NSAttributedString()
let tempNSView = NSTextField()
switch tableColumn {
case tableView.tableColumns[0]:
attributedString = NSAttributedString(string: closingValues[row].name, attributes: attributes1)
case tableView.tableColumns[1]:
attributedString = NSAttributedString(string: closingValues[row].date, attributes: attributes1)
case tableView.tableColumns[2]:
let closeAsString = String(format: "$%.2f", closingValues[row].close)
attributedString = NSAttributedString(string: closeAsString, attributes: attributes1)
default:
print("problem in table view switch statement")
}
tempNSView.backgroundColor = NSColor.white
tempNSView.isBordered = true
tempNSView.isEditable = false
tempNSView.attributedStringValue = attributedString
nsView = tempNSView
return nsView
}
} // end of coordinator class
func makeNSView(context: Context) -> NSScrollView {
let tableView = NSTableView()
tableView.style = .plain
tableView.delegate = context.coordinator
tableView.dataSource = context.coordinator
tableView.addTableColumn(NSTableColumn())
tableView.addTableColumn(NSTableColumn())
tableView.addTableColumn(NSTableColumn())
tableView.intercellSpacing = NSSize(width: 0.0, height: 0.0)
tableView.headerView?.frame.size.height = 20.0
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .center
let attributes: [NSAttributedString.Key: Any] = [
.foregroundColor: NSColor.black,
.paragraphStyle: paragraphStyle,
.font: NSFont.systemFont(ofSize: 18)
]
let column0AttributedString = NSAttributedString(string: "Stock", attributes: attributes)
let column0Header = tableView.tableColumns[0]
column0Header.headerCell.drawsBackground = true
column0Header.headerCell.backgroundColor = NSColor.systemMint
column0Header.headerCell.alignment = .center
column0Header.headerCell.attributedStringValue = column0AttributedString
column0Header.sizeToFit()
column0Header.minWidth = 90.0
column0Header.maxWidth = 90.0
let column1AttributedString = NSAttributedString(string: "Date", attributes: attributes)
let column1Header = tableView.tableColumns[1]
column1Header.headerCell.drawsBackground = true
column1Header.headerCell.backgroundColor = NSColor.systemMint
column1Header.headerCell.alignment = .center
column1Header.headerCell.attributedStringValue = column1AttributedString
column1Header.sizeToFit()
column1Header.minWidth = 125.0
column1Header.maxWidth = 125.0
let column2AttributedString = NSAttributedString(string: "Closing", attributes: attributes)
let column2Header = tableView.tableColumns[2]
column2Header.headerCell.drawsBackground = true
column2Header.headerCell.backgroundColor = NSColor.systemMint
column2Header.headerCell.alignment = .center
column2Header.headerCell.attributedStringValue = column2AttributedString
column2Header.sizeToFit()
column2Header.minWidth = 90.0
column2Header.maxWidth = 90.0
let scrollView = NSScrollView()
scrollView.documentView = tableView
return scrollView
}
func updateNSView(_ nsView: NSScrollView, context: Context) {
let tableView = (nsView.documentView as! NSTableView)
print("in update ns view")
// work on this section
}
}
I have a program that creates a custom table view. In the delegate that populates the cells with data I create an instance of a custom NSTableCellView. It works. What I would like to be able to do is pass in a value when making an instance so that I can set the width of the frame (var rectWidth in the custom NSTableCellView). I am currently using two different custom NSTableCellViews, each with a different value for var rectWidth. Below is my delegate and custom NSTableCellView code.
func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
if (tableColumn?.identifier)!.rawValue == "fund" {
let dataCell = CustomTableCellView()
dataCell.textField?.stringValue = closingValues[row].fundName
return dataCell
} else if (tableColumn?.identifier)!.rawValue == "date" {
let dataCell = CustomTableCellViewDate()
dataCell.textField?.stringValue = SQLDateFormatter.string(from: closingValues[row].timeStamp)
return dataCell
} else {
let dataCell = CustomTableCellView()
dataCell.textField?.stringValue = String(format: "$%.2f", closingValues[row].close)
return dataCell
}
}
class CustomTableCellView: NSTableCellView {
override init(frame frameRect: NSRect) {
super.init(frame: frameRect)
let rectWidth: CGFloat = 100
self.autoresizingMask = .width
let nsRectangle = NSMakeRect(0, 0, rectWidth, 24)
let customTextField: NSTextField = CustomTextField(frame: nsRectangle)
self.textField = customTextField
self.addSubview(customTextField)
}
required init?(coder decoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
I am creating a user interface for a working program. I am able to lay things out with offsets but am trying as a learning experience to do the same with alignment guides. For the section heading labeled "Group 1" I am able to get the layout I want. What I cannot get to work are alignment guides for the associated rounded rectangle. It appears that the alignment guides with the rounded rectangle only affect the contents i.e. the text "Data Table". Below is a picture of the code output and the code. How, using alignment guides, can move the top rounded rectangle? To keep the picture small I just copied the left side of the output window. The top rounded rectangle is approximately centered in this window.
struct ContentView: View {
var body: some View {
NavigationStack {
Text("Group1")
.font(Font.custom("Arial", size: 16))
.alignmentGuide(HorizontalAlignment.center, computeValue: { d in
print("\(d[HorizontalAlignment.leading])")
// print leading = 0.0
// print center = 27
// print trailing = 54
return d[HorizontalAlignment.leading] + 255
})
ZStack (alignment: Alignment(horizontal: .center, vertical: .center)) {
RoundedRectangle(cornerRadius: 10)
.fill(.white)
.alignmentGuide(HorizontalAlignment.center, computeValue: { d in
return d[HorizontalAlignment.leading] + 45
})
VStack (alignment: HorizontalAlignment.leading) {
NavigationLink(value: "Table1") {
Text("Data Table")
}
.font(Font.custom("Arial", size: 14))
.buttonStyle(.link)
.underline()
.focusable(false)
} // end vstack
} // end zStack
.frame(width: 200, height: 60)
Text("Group2")
.font(Font.custom("Arial", size: 16))
.frame(width: 600, height: 20, alignment: .leading)
.padding(.leading, 35)
.padding(.top, 20)
.offset(x: 30)
ZStack {
RoundedRectangle(cornerSize: CGSize(width: 200, height: 60))
.stroke(Color(.clear), lineWidth: 1)
.frame(width: 200, height: 60, alignment: .leading)
.background(.white)
.cornerRadius(10)
.offset(x: -160)
VStack () {
NavigationLink(value: "Table2") {
Text("Data Table")
}
.font(Font.custom("Arial", size: 14))
.buttonStyle(.link)
.underline()
.padding(.leading, 8)
.frame(width: 200, height: 20, alignment: .leading)
.offset(x: -160)
.focusable(false)
}
}
Text("Group3")
.font(Font.custom("Arial", size: 16))
.frame(width: 600, height: 20, alignment: .leading)
.padding(.leading, 35)
.padding(.top, 20)
.offset(x: 30)
ZStack {
RoundedRectangle(cornerSize: CGSize(width: 200, height: 60))
.stroke(Color(.clear), lineWidth: 1)
.frame(width: 200, height: 60, alignment: .leading)
.background(.white)
.cornerRadius(10)
.offset(x: -160)
VStack () {
NavigationLink(value: "Table3") {
Text("Data Table")
}
.font(Font.custom("Arial", size: 14))
.buttonStyle(.link)
.underline()
.padding(.leading, 8)
.frame(width: 200, height: 20, alignment: .leading)
.offset(x: -160)
.focusable(false)
}
}
.padding(.bottom, 20)
.navigationDestination(for: String.self) { command in
switch command {
case "Table1":
HStack {
CustomTableView(fundName: "Table1", numYears: 1)
.frame(width: 320, height: 345, alignment: .center)
.padding(.leading, 120)
.padding(.trailing, 160)
}
case "Table2":
HStack {
CustomTableView(fundName: "Table2", numYears: 1)
.frame(width: 320, height: 345, alignment: .center)
.padding(.leading, 120)
.padding(.trailing, 160)
}
case "Table3":
HStack {
CustomTableView(fundName: "Table3", numYears: 1)
.frame(width: 320, height: 345, alignment: .center)
.padding(.leading, 120)
.padding(.trailing, 160)
}
default:
let _ = print("problem in main view switch statement")
} // end switch
} // end navigation destination
}
.frame(width: 600, height: 400, alignment: .trailing)
}
}
I have a swift program that displays a chart using Chart. The code includes an X Axis Scale parameter but for some reason the last value (right most) on the x axis does not display. It should display Aug 2023. In checking the array used for the x axis labels I find that the last value is Aug 2023. I do not know how to overcome this obstacle. Any assistance will be appreciated. Below is a picture of the bottom of the chart and the code.
struct CustomChartView: View {
let vm: SQLDataVM = SQLDataVM.shared
let closingValues: [TradingDay]
let fundName: String
let numYears: Int
let maxCloseStruct: TradingDay
let maxClose: Double
let minCloseStruct: TradingDay
let minClose: Double
let yIncrment: Double
let yAxisValues: [Double]
let minTimeStampStruct: TradingDay
let minTimeStamp: Date
var dateComponent = DateComponents()
let maxTimeStampStruct: TradingDay
let maxTimeStamp: Date
var xAxisValues: [Date] = []
init (fundName: String, numYears: Int) {
self.fundName = fundName
self.numYears = numYears
closingValues = self.vm.QueryDatabase(fundName: fundName, numYears: numYears)
maxCloseStruct = self.closingValues.max(by: { (tradingDay1, tradingDay2) -> Bool in
return tradingDay1.close < tradingDay2.close
})!
maxClose = maxCloseStruct.close
minCloseStruct = closingValues.min(by: { (tradingDay1, tradingDay2) -> Bool in
return tradingDay1.close < tradingDay2.close
})!
minClose = minCloseStruct.close
yIncrment = (maxClose - minClose)/4
yAxisValues = [
minClose,
minClose + (1 * yIncrment),
minClose + (2 * yIncrment),
minClose + (3 * yIncrment),
maxClose
]
minTimeStampStruct = closingValues.min(by: { (tradingDay1, tradingDay2) -> Bool in
return tradingDay1.timeStamp < tradingDay2.timeStamp
})!
minTimeStamp = minTimeStampStruct.timeStamp
maxTimeStampStruct = closingValues.max(by: { (tradingDay1, tradingDay2) -> Bool in
return tradingDay1.timeStamp < tradingDay2.timeStamp
})!
maxTimeStamp = maxTimeStampStruct.timeStamp
xAxisValues.append(minTimeStamp)
for i in 1...11 {
dateComponent.month = i
let nextMonth = Calendar.current.date(byAdding: dateComponent, to: minTimeStamp)
xAxisValues.append(nextMonth!)
}
xAxisValues.append(maxTimeStamp)
print("\(xAxisValues[12])") // prints 2023-08-04 00:00:00 +0000
} // end init
var body: some View {
HStack(alignment: .center) {
VStack(alignment: .center) {
Chart(closingValues, id:\.id) {
LineMark(
x: .value("Date", $0.timeStamp, unit: .day),
y: .value("Closing", $0.close)
)
.foregroundStyle(.blue)
} // end chart
.frame(width: 1000, height: 700, alignment: .center)
.chartXAxisLabel(position: .bottom, alignment: .center, spacing: 15) {
Text("Date")
.font(.custom("Arial", size: 20))
}
.chartYAxisLabel(position: .leading, alignment: .center, spacing: 20) {
Text("Closing Value")
.font(.custom("Arial", size: 20))
}
.chartXAxis {
AxisMarks(values: xAxisValues) { value in
if let date = value.as(Date.self) {
AxisValueLabel(horizontalSpacing: -14, verticalSpacing: 10) {
VStack(alignment: .leading) {
Text(ChartMonthFormatter.string(from: date))
.font(.custom("Arial", size: 14))
Text(ChartYearFormatter.string(from: date))
.font(.custom("Arial", size: 14))
} // end v stack
} // end axis label
} // end if statement
AxisGridLine(centered: true, stroke: StrokeStyle(lineWidth: 1))
.foregroundStyle(Color.black)
AxisTick(centered: true, length: 0, stroke: .none)
}
} // end chart x axis
.chartXScale(domain: [xAxisValues[0], xAxisValues[12]])
.chartYAxis {
AxisMarks(position: .leading, values: yAxisValues) { value in
AxisGridLine(centered: true, stroke: StrokeStyle(lineWidth: 1))
.foregroundStyle(Color.black)
AxisTick(centered: true, length: 0, stroke: .none)
AxisValueLabel(horizontalSpacing: 10) {
if let yAxisValue = value.as(Double.self) {
let stringValue = String(format: "$%.02f", yAxisValue)
Text(stringValue)
.font(.custom("Arial", size: 14))
}
}
}
}
.chartYScale(domain: [minClose, maxClose])
.chartPlotStyle { plotArea in
plotArea.background(.white.opacity(0.9))
.border(.black, width: 1)
} // end chart plot style
} // end v stack
.frame(width: 1200, height: 900, alignment: .center)
} // end h stack
} // end some view
}
I have a program that utilizes a Navigation Stack. I want each view to be centered on the screen and be a specific size. I accomplished this with some position logic which sets the views frame size and origin. There is unique position logic for each of the 3 view sizes, the Content View and 2 navigation destination views. When the Content View is first displayed the associated position logic code runs and the view is the correct size and centered. The same is true every time one of the 2 navigation destination views is displayed. Unfortunately, when I return to the Content View from a navigation destination view the position logic does not run again and the Content View is now the same size and position as the previous navigation destination view. How do I resolve this problem? Below is the position logic code associated with the Content View and how it is called.
@main
struct TableViewTestApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.hostingWindowPositionHome(
screen: .main
)
}
}
}
extension View {
func hostingWindowPositionHome(
screen: NSScreen? = nil
) -> some View {
modifier(
WindowPositionModifierHome(
screen: screen
)
)
}
}
private struct WindowPositionModifierHome: ViewModifier {
let screen: NSScreen?
func body(content: Content) -> some View {
content.background(
HostingWindowFinderHome {
$0?.setPositionHome(in: screen)
}
)
}
}
private struct HostingWindowFinderHome: NSViewRepresentable {
var callback: (NSWindow?) -> ()
func makeNSView(context: Self.Context) -> NSView {
let view = NSView()
DispatchQueue.main.async { self.callback(view.window) }
return view
}
func updateNSView(_ nsView: NSView, context: Context) {
DispatchQueue.main.async { self.callback(nsView.window) }
}
}
extension NSWindow {
func setPositionHome(in screen: NSScreen?) {
let nsRectangle: NSRect = NSRect(x: 1055.0, y: 370.0, width: 450, height: 700)
setFrame(nsRectangle, display: true)
}
}
I have a program that uses 3 different windows, each in their own window group. In a button I can use openWindow() to call another window and it works perfectly. I watched the video at the link below and now am trying to convert my program to use a navigation stack instead of buttons. I got things to work using the code listed at the link with a few changes but am unable to get the navigation destination to use openWindow. I attempted to create a view builder but could not get it to work. After some additional research I am starting to think that the navigation destination expects to use the same window as the root view not a separate window/view and therefore, navigation destination wants just a view. But I am unsure. If someone could provide some guidance it would be appreciated.
https://developer.apple.com/videos/play/wwdc2022/10054/
struct ContentView: View {
@Environment (\.openWindow) private var openWindow
@StateObject private var dataModel = DataModel()
var body: some View {
VStack(alignment: .center) {
NavigationStack() {
List(Sections.allCases) { section in
Section(section.localizedName) {
ForEach(dataModel.stocks(in: section)) { stock in
NavigationLink(stock.listingName, value: stock)
.font(Font.custom("Arial", size: 16))
}
} // end section
} // end list
.scrollContentBackground(.hidden)
.background(Color.mint)
.navigationTitle("Stocks")
.navigationDestination(for: StockData.self) { stock in
Text("\(stock.listingName) - \(stock.name)")
// GenericTableView(content: openWindow(id: "table", value: stock.name))
// Cannot convert value of type '()' to expected argument type '() -> ContentView'
}
} // end navigation stack
} // end v stack
}
}
struct GenericTableView<Content:View>: View {
let content: Content
init(@ViewBuilder content: () -> Content) {
self.content = content()
}
var body: some View {
content
}
}
Hello,
I have a swift program that allows me to transition from a primary view controller to a secondary view controller. To complete this task I create a segue between a button on the primary view controller and the secondary view controller by dragging from the button to the secondary view controller then assigning an identifier to this seque. The balance is handled programatically.
What I would like to do is eliminate the creation of the segue via dragging and handle transitioning to the secondary view controller 100% in code. I have given the secondary view controller a storyboard id so it seems logical to me that I should be able to locate the secondary view controller via this identifier and use this to transition to it.
Is there a way to do this?
Regards,
Chris
Hello,
I have a Swift program. It utilizes the SwiftUI.
I want to place my frame/container in the center of the computer screen. Any advise on how to do so would be appreciated.
Below is what I have so far.
Regards,
Chris
import SwiftUI
@main
struct Test1App: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
import SwiftUI
struct ContentView: View {
var body: some View {
Text("Hello, world!")
.frame(width: 500, height: 350)
.background(Color .blue)
.padding()
}
}
Hello,
I am trying to learn Swift. I have the code below.
With a button click I can move to a new view. What I would like to do is once the new view is displayed have the navigation link destination changed to "CurrentView" and the button text to "Previous View".
Any insight on how to resolve this issue would be appreciated.
Regards,
Chris
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
NavigationLink(destination: NextContentView()){
Text("Next View")
}
}
}
}