I'm a bit out of ideas here. I want a very simple thing: to be able to select a given GtkListBox row programmatically and then scroll the list box (which is wrapped in a ScrolledWindow and a Viewport).
Selecting a row is trivial (my code is Go & gotk3, but that's not so important):
listBox.SelectRow(row)
But scrolling to the row proved to be a real challenge. Whatever I tried, I failed:
I tried to focus the row, but it helped nothing
I tried to figure out the row's Y-coordinate using gtk_widget_translate_coordinates(), but it returns -1 for any row
Perhaps I can find out which row is at the top and the bottom of the list box and use that to scroll the ScrolledWindow but I can't figure out how to do that.
Update: I've tried what's proposed here: Manually scroll to a child in a Gtk.ScrolledWindow, but it didn't work as still no scrolling occurred:
listbox.SelectRow(rowToSelect)
listbox.SetFocusVAdjustment(listbox.GetAdjustment())
if rowToSelect != nil {
rowToSelect.GrabFocus()
}
I also tried the same with rowToSelect's child using the code below, to no avail:
if c, err := rowToSelect.GetChild(); err == nil {
c.GrabFocus()
}
I've finally nailed it thanks to the hint by Emmanuel Touzery. I didn't have to go as far as to use timers, but the problem was indeed that at the moment of filling of the list box the row hasn't been realised yet so no coordinate translation could possibly happen.
What I did is scheduled the scrolling using GLib's idle_add(), which makes it happen later downstream, and that seemed to have worked perfectly: see this commit for details.
In short, it all boils down to the following code:
func ListBoxScrollToSelected(listBox *gtk.ListBox) {
// If there's selection
if row := listBox.GetSelectedRow(); row != nil {
// Convert the row's Y coordinate into the list box's coordinate
if _, y, _ := row.TranslateCoordinates(listBox, 0, 0); y >= 0 {
// Scroll the vertical adjustment to center the row in the viewport
if adj := listBox.GetAdjustment(); adj != nil {
_, rowHeight := row.GetPreferredHeight()
adj.SetValue(float64(y) - (adj.GetPageSize()-float64(rowHeight))/2)
}
}
}
}
The above function has to be called using the glib.IdleAdd() and not in the code that fills the list box.
So, I had the same issue but managed to make it work in my case. I think there are good chances my solution will work for you too.
Since the grab_focus method didn't work, I started implementing a workaround solution using listbox_get_row_at_y. Highly unsatisfying, but hopefully it was going to work. And.. it didn't work, because get_row_at_y would always return null, for all the y values I'd feed it. And I knew the listbox wasn't empty. So that made me realize I was trying to focus a row that I had just been adding to the listbox.. The row wasn't realized yet, it couldn't be focused because it wasn't ready for that yet.
So I changed my code to fill the listbox, wait a 100ms timeout, and only then call grab_focus. And that worked!
I'm actually using a library which is wrapping the timeout call for me, but I think you could use g_timeout_add in 'raw' gtk for that purpose.
Note that this means that calling grab_focus on a listbox that was already filled beforehand and the items realized on screen should work directly. If that's your situation then this won't help you.
Related
I'm using Unidoc's unipdf library to generate a pdf with multiple tables in it.
When the content in a table cell is huge and needs to span over multiple pages, the pdf generated has the cells in the row scrambled, each cell goes over to a new page and no data is being displayed in the cell which has the huge data.
And in the same scenario some times I see this process hangs and also starts eating up a lot of memory.
Here are the screenshots of the same:
Page1/cell1 - the cell spans the entire page but has only one line
Page2/cell2 - with actual huge data, but no data being displayed
Page3/cell3 - the cell spans the entire page but has only one line
The code snippet for doing the above:
func AddTableCell(c *ctx.Context, t *creator.Table, parag *creator.Paragraph, colSpan int, width float64, sides ...creator.CellBorderSide) {
cell := t.MultiColCell(colSpan)
for _, s := range sides {
cell.SetBorder(s, creator.CellBorderStyleSingle, width)
}
cell.SetHorizontalAlignment(creator.CellHorizontalAlignmentLeft)
cell.SetVerticalAlignment(creator.CellVerticalAlignmentMiddle)
err := cell.SetContent(parag)
c.NoError(err, "error setting cell content: %v", err)
}
func NewParagraph(c *creator.Creator, text string, font *pdfmodel.PdfFont, fontSize, lineHeight float64) *creator.Paragraph {
parag := c.NewParagraph(text)
parag.SetFont(font)
parag.SetFontSize(fontSize)
parag.SetColor(reportTextColor)
parag.SetLineHeight(lineHeight)
parag.SetEnableWrap(true)
return parag
}
These are my two functions which help me draw the table
And here is how I use them:
for col := 0; col < len(rowVals); col++ {
if col == 0 {
AddTableCell(g.c, tb.Table, NewParagraph(g.Creator, rowVals[col], font, 10, 1.5),
colSpans[col], tb.cellBorderWidth, creator.CellBorderSideAll)
} else {
AddTableCell(g.c, tb.Table, NewParagraph(g.Creator, rowVals[col], font, 10, 1.5),
colSpans[col], tb.cellBorderWidth, creator.CellBorderSideTop, creator.CellBorderSideRight, creator.CellBorderSideBottom)
}
if g.c.HasErr() {
return
}
}
Using the same logic I'm able generate pdf for smaller piece of data but it breaks when the data is huge as shown in the screenshots above.
Does unidoc support handling data spanning multiple pages when embeded within tables? Or does it have some option/flag to enable it? What is it that I'm missing here?
Another approach which you can use is
create GO HTML template and render it.
Use wkhtmltopdf to convert html to pdf.
I also faced similar issues where I was unable to generate a complex pdf and using wkhtmltopdf I was able to generate it.
ps: you can use pdfg.AddPage to add new page.
The newest release UniPDF v3.16.0 (just released) adds support for row-wrapping, and can be enabled via EnableRowWrap on the table:
t.EnableRowWrap(true)
We have verified that it works with your example posted above.
If you continue seeing large use of resources in the newest versions, please share with us. We have made some pretty big performance enhancements recently and will continue to improve it. Getting good bug reports is a great step towards that.
Disclosure: I am the original developer of UniPDF.
New to Go and Fyne, and stumbling trying to get what I need out of Fyne. Sorry, this will be long.
My problem is this. I’m writing a application that gets a list of commands from a server, telling it to create a series of widgets and display them. They are of various types – Label, Button, Entry, Select, etc.
But these aren’t standard widgets; I need to extend their behavior a bit. For one thing, when operated by the user, they each need access to some per-widget information. Button click, for example, has to reference some data specific to that button so it knows what to do. We’ll call this additional information the About struct.
Secondly, every widget needs to be able to take a right click and drop down a widget specific menu. Yes, even buttons and labels need to be able to provide drop down menus. In the case of a widget like Entry, I know this design is going to condemn me to having to write my own menu choices for Paste, Copy and the other operations Entry normally offers on a right click, but I’m ok with that.
I have all this working, but in the process I broke Select (and probably there will be breakage for other widgets.) and I can’t see how to fix it.
Problem: trying to send the Select widget causes a panic: interface conversion: fyne.Canvas is nil, not *glfw.glCanvas
Approach:
type GenericWidget struct {
fyne.Widget //I’m some kind of widget
about *About //here’s my personal “About” data
//function pointers
OnRightClickp func(gw *GenericWidget, pe *fyne.PointEvent)
OnLeftClickp func(gw *GenericWidget, pe *fyne.PointEvent)
…other “function pointers” for OnRunep and so on…
}
And now I have to catch all “events” so GenericWidget will see them:
func (gw *GenericWidget) TappedSecondary(pe *fyne.PointEvent) {
if (gw.OnRightClickp != nil) {gw.OnRightClickp(gw, pe)}
}
func (gw *GenericWidget) Tapped(pe *fyne.PointEvent) {
if (gw.OnLeftClickp != nil){gw.OnLeftClickp(gw, pe)}
}
//type Focusable interface
//etc….
This should represent any single widget, regardless of type. It’s not complicated: When Tapped is invoked by the driver, GenericWidget.Tapped gets called. If this widget has a function pointer for “OnLeftClickp” set, call it. Crucially, we pass a pointer to the widget itself when that happens, because all the event handlers I write will need access to the *About and maybe anything else I add to GenericWidget.
Creation is simple enough:
func NewGenericWidget(w fyne.Widget, about *About) *GenericWidget {
gw := GenericWidget{w, about, nil, nil, nil, nil, nil, nil, nil, nil}
return &gw
}
And when it’s time to create a Label, I do that and fold it into a GenericWidget
func NewExtendedLabelWithStyle( //Label with catachable left and right click
text string,
about *About,
alignment fyne.TextAlign,
style fyne.TextStyle,
tappedLeft func(*GenericWidget, *fyne.PointEvent),
tappedRight func(*GenericWidget, *fyne.PointEvent)) *GenericWidget {
e := NewGenericWidget(widget.NewLabelWithStyle(text, alignment, style), about)
e.OnLeftClickp = tappedLeft
e.OnRightClickp = tappedRight
return e
}
All these GenericWidgets work fine – I add them to the appropriate Box and the window paints as I’d expect. I can right click on a label and if OnRightClickp is set, which is generally is, code gets called and is given access to *GenericWidget, which leads to *About, which means the menu that gets put up can offer all the right stuff for what’s in this label.
Of course, Labels don’t normally care about clicking, so the fact that I’ve stolen all the calls in Tappable doesn’t matter.
But a Select widget does care about left clicks, so the fact that GenericWidget is intercepting the call to Tapped() means I’d never see the dropdown appear.
No problem, I thought. When I create the Select widget and the surrounding GenericWidget, I’ll just specify I want to call Select’s Tapped myself:
func NewExtendedSelect(about *About, sel func(*GenericWidget, string)) *GenericWidget {
//build the options. NewSelect demands a slice of strings, so...
st := make([]string, 64)
for e := about.theList.Front(); e != nil; e = e.Next() {
st = append(st, e.Value.(string))
}
s := widget.NewSelect(st, func(c string){})
//make sure it selects the text it should, initially
s.SetSelected(about.value)
//wrap it
e := NewGenericWidget(s, about)
//e.OnChangedp = sel //not set up yet (and don’t know how)
//HERE BE DRAGONS --------------
//But we don't want to break left click. So when we intercept it,
// pass it down to the actual Selection widget:
e.OnLeftClickp = func(me* GenericWidget, pe *fyne.PointEvent) {
fmt.Println("select tapped")
//call the Tapped that Select knows about:
s.Tapped(pe) //PANIC!
}
// -----------------------------
//Handle right click with our usual menu magic
e.OnRightClickp =func(me* GenericWidget, pe *fyne.PointEvent) {
//defer used because not sure what to do with the return value, so make it Go's problem
defer widget.NewPopUpMenuAtPosition(me.GetRightClickMenu(),
me.about.sheet.window.Canvas(), pe.AbsolutePosition)
}
return e //here's your GenericWidget, ready to drop into a Fyne container.
}
Compiles fine, Selects get displayed, but when I left click it prints the expected “select tapped” and then immediately panics:
select tapped
panic: interface conversion: fyne.Canvas is nil, not *glfw.glCanvas
I’m lost. My GenericWidget is just a widget; I thought that’s what composition did, and all the GenericWidgets I create are put in a Box which is in a Box which is SetContent into the window. But the error is suggesting to me that somehow this Select object wasn’t set up right and when it goes to draw the options, something is missing. What did I do wrong?
It’s possible my whole approach is wrong (I do a lot of C++ and Python and I take an OO view of things). In that case, how do I do all this?
This turns out to have been a Fyne bug, which has since been fixed.
It does not look like the select is being composed - your extended select is just creating a new one, tapping it later.
The crash is coming from it trying to display a pop up next to a select that has not been found on the canvas.
If you are extending builtin widgets you also need to call ExtendBaseWidget so that the driver can lookup your widget instead of the default one.
That said a single widget that can extend any other type of widget kind of goes against the strongly types design of Fyne APIs and you may run in to trouble.
I am writing an UI test case, in which I need to perform an action, and then on the current page, scroll the only UITableView to the bottom to check if specific text shows up inside the last cell in the UITableView.
Right now the only way I can think of is to scroll it using app.tables.cells.element(boundBy: 0).swipeUp(), but if there are too many cells, it doesn't scroll all the way to the bottom. And the number of cells in the UITableView is not always the same, I cannot swipe up more than once because there might be only one cell in the table.
One way you could go about this is by getting the last cell from the tableView. Then, run a while loop that scrolls and checks to see if the cell isHittable between each scroll. Once it's determined that isHittable == true, the element can then be asserted against.
https://developer.apple.com/documentation/xctest/xcuielement/1500561-ishittable
It would look something like this (Swift answer):
In your XCTestCase file, write a query to identify the table. Then, a subsequent query to identify the last cell.
let tableView = app.descendants(matching: .table).firstMatch
guard let lastCell = tableView.cells.allElementsBoundByIndex.last else { return }
Use a while loop to determine whether or not the cell isHittable/is on screen. Note: isHittable relies on the cell's userInteractionEnabled property being set to true
//Add in a count, so that the loop can escape if it's scrolled too many times
let MAX_SCROLLS = 10
var count = 0
while lastCell.isHittable == false && count < MAX_SCROLLS {
apps.swipeUp()
count += 1
}
Check the cell's text using the label property, and compare it against the expected text.
//If there is only one label within the cell
let textInLastCell = lastCell.descendants(matching: .staticText).firstMatch
XCTAssertTrue(textInLastCell.label == "Expected Text" && textInLastCell.isHittable)
Blaines answer lead me to dig a little bit more into this topic and I found a different solution that worked for me:
func testTheTest() {
let app = XCUIApplication()
app.launch()
// Opens a menu in my app which contains the table view
app.buttons["openMenu"].tap()
// Get a handle for the tableView
let listpagetableviewTable = app.tables["myTableView"]
// Get a handle for the not yet existing cell by its content text
let cell = listpagetableviewTable.staticTexts["This text is from the cell"]
// Swipe down until it is visible
while !cell.exists {
app.swipeUp()
}
// Interact with it when visible
cell.tap()
}
One thing I had to do for this in order to work is set isAccessibilityElement to true and also assign accessibilityLabel as a String to the table view so it can be queried by it within the test code.
This might not be best practice but for what I could see in my test it works very well. I don't know how it would work when the cell has no text, one might be able to reference the cell(which is not really directly referenced here) by an image view or something else. It's obviously missing the counter from Blaines answer but I left it out for simplicity reasons.
I have a dc.rowchart that has 5 different "categories". Initially, all are selected. When I click on one, then only that one is highlighted. When I click on a second one... both the first and second one I clicked are highlighted.
How can I make it/configure the rowchart such that only a single category is highlighted every time a bar is clicked?
dc.filter("category1");
dc.filter("category2");
Both of these in sequence appear to "append" filters than replace.
Ethan's answer is almost there. It's likely unintentional, but dc.js doesn't appear to use the return value for addFilterHandler, so you'll have to modify the filters parameter for it to work, like so:
myChart.addFilterHandler(function (filters, filter) {
filters.length = 0; // empty the array
filters.push(filter);
return filters;
});
This works great as long as your chart doesn't use cap (e.g. a pie chart with limited slices), as this handler prevents the others group from working. I've yet to come up with a satisfactory solution for that case, unfortunately.
I assume you'll want addFilterHandler - https://github.com/dc-js/dc.js/blob/master/web/docs/api-latest.md#dc.baseMixin+addFilterHandler
You'd probably want to do the following, but it's untested.
myChart.addFilterHander(function (filters, filter) {
return [filter];
});
I am using xCode 7.1. I would like to automate interaction with all cells from a table/collection view. I would expect it to be something like this:
for i in 0..<tableView.cells.count {
let cell = collectionView.cells.elementBoundByIndex(i)
cell.tap()
backBtn.tap()
}
However this snippet only queries current descendants of the table view, so it will loop through the first m (m < n) loaded cells out of total n cells from the data source.
What is the best way to loop through all cells available in data source? Obviously querying for .Cell descendants is not the right approach.
P.S.: I tried to perform swipe on table view after every tap on cell. However it swipes to far away (scrollByOffset is not available). And again, don't know how to extract total number of cells from data source.
Cheers,
Leonid
So problem here is that you cannot call tap() on a cell that is not visible. SoI wrote a extension on XCUIElement - XCUIElement+UITableViewCell
func makeCellVisibleInWindow(window: XCUIElement, inTableView tableView: XCUIElement) {
var windowMaxY: CGFloat = CGRectGetMaxY(window.frame)
while 1 {
if self.frame.origin.y < 0 {
tableView.swipeDown()
}
else {
if self.frame.origin.y > windowMaxY {
tableView.swipeUp()
}
else {
break
}
}
}
}
Now you can use this method to make you cell visible and than tap on it.
var window: XCUIElement = application.windows.elementBoundByIndex(0)
for i in 0..<tableView.cells.count {
let cell = collectionView.cells.elementBoundByIndex(i)
cell.makeCellVisibleInWindow(window, inTableView: tableView)
cell.tap()
backBtn.tap()
}
let cells = XCUIApplication().tables.cells
for cell in cells.allElementsBoundByIndex {
cell.tap()
cell.backButton.tap()
}
I face the same situation however from my trials, you can do tap() on a cell that is not visible.
However it is not reliable and it fails for an obscur reason.
It looks to me that this is because in some situation the next cell I wanted to scroll to while parsing my table was not loaded.
So here is the trick I used:
before parsing my tables I first tap in the last cell, in my case I type an editable UITextField as all other tap will cause triggering a segue.
This first tap() cause the scroll to the last cell and so the loads of data.
then I check my cells contents
let cells = app.tables.cells
/*
this is a trick,
enter in editing for last cell of the table view so that all the cells are loaded once
avoid the next trick to fail sometime because it can't find a textField
*/
app.tables.children(matching: .cell).element(boundBy: cells.count - 1).children(matching: .textField).element(boundBy: 0).tap()
app.typeText("\r") // exit editing
for cellIdx in 0..<cells.count {
/*
this is a trick
cell may be partially or not visible, so data not loaded in table view.
Taping in it is will make it visible and so do load the data (as well as doing a scroll to the cell)
Here taping in the editable text (the name) as taping elsewhere will cause a segue to the detail view
this is why we just tap return to canel name edidting
*/
app.tables.children(matching: .cell).element(boundBy: cellIdx).children(matching: .textField).element(boundBy: 0).tap()
app.typeText("\r")
// doing my checks
}
At least so far it worked for me, not sure this is 100% working, for instance on very long list.