{"id":6473,"date":"2007-03-19T13:47:00","date_gmt":"2007-03-19T13:47:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/vbteam\/2007\/03\/19\/coding-a-euchre-game-part-5-modality-is-a-crutch-matt-gertz\/"},"modified":"2024-07-05T14:49:15","modified_gmt":"2024-07-05T21:49:15","slug":"coding-a-euchre-game-part-5-modality-is-a-crutch-matt-gertz","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/vbteam\/coding-a-euchre-game-part-5-modality-is-a-crutch-matt-gertz\/","title":{"rendered":"Coding a Euchre Game, Part 5: Modality is a crutch (Matt Gertz)"},"content":{"rendered":"

Coding a Euchre Game, Part 5: Modality is a crutch<\/span><\/font><\/font><\/font><\/h2>\n

It\u2019s really tempting to rely on modal dialogs in a program.  <\/span>It forces the user to pay attention to what you feel is the most important thing.  <\/span>However, modal dialogs can also be frustrating to users and you should be careful about when you use them.  <\/span>To illustrate this point, let\u2019s consider the Euchre game again.  <\/span>At some point, the user is going to be asked to play a card.  <\/span>Ideally, you don\u2019t want the user to do anything else because there isn\u2019t anything else the user can do \u2013 right?  <\/span>Well, no exactly.  <\/span>Remember that the user needs to be able to start a new game, or possibly close the game.  <\/span>I talked a bit about this earlier in parts three and four of this series, but only as far as adding a message pump while the AI was operating.  <\/span>In this case, though, it\u2019s not the AI that\u2019s active, but the player.  <\/span>If the user is presented with a modal dialog, he or she is effective barred from closing the app (or restarting it), unless you do something lame like add a \u201cquit game\u201d or \u201cnew game\u201d button to the dialog which the user would have to look at on every hand.  <\/span>Furthermore, the modal dialog just won\u2019t look as good for gameplay \u2013 the user will be expecting to click on a card instead, as that\u2019s far more intuitive.<\/font><\/p>\n

We need a better system; some way to get the user to click the card and yet give them a chance to quit or restart the game as well.  <\/span>Furthermore, we want them to click a valid card \u2013 Euchre is a game where you have to play the same suit that was led (if you have such a card). This all actually turns out to be easy; we\u2019ll just enable the relevant cards and add a message pump to handle events:<\/font><\/p>\n

            <\/span>If<\/span> Seat = Seats.Player Then <\/span>‘ This is the human being player<\/span><\/span><\/p>\n

 <\/span><\/p>\n

            <\/span>   <\/span><\/span>‘ First, turn on the \u201cplay a card\u201d sign:<\/span><\/span><\/p>\n

                <\/span>Table.SelectLabel.Text = My<\/span>.Resources.Notice_PlayACard<\/span><\/p>\n

 <\/span><\/p>\n

            <\/span>  <\/span>‘ Assume the player has no cards which follow suit<\/span><\/span><\/p>\n

                <\/span>Dim<\/span> AnyValid As<\/span> Boolean<\/span> = False<\/span><\/span><\/p>\n

 <\/span><\/p>\n

            <\/span>  <\/span><\/span>‘ Check each remaining card in the player\u2019s hand<\/span><\/p>\n

            <\/span>  <\/span>‘ to see if it would follow suit<\/span><\/span><\/p>\n

                <\/span>Dim<\/span> i As<\/span> Integer<\/span><\/span><\/p>\n

                <\/span>For<\/span> i = 0 To<\/span> 4<\/span><\/p>\n

                    <\/span>If<\/span> Me<\/span>.CardsHeldThisHand(i) IsNot<\/span> Nothing<\/span> Then<\/span><\/span><\/p>\n

                        <\/span>‘ Note that the leader can play any card;<\/span><\/span><\/p>\n

                        <\/span>‘<\/span> he\/she selects the suit to be followed.<\/span><\/span><\/p>\n

If<\/span> Table.LeaderThisTrick <> Seat Then<\/span><\/span><\/p>\n

                            <\/span>If<\/span> Not<\/span> CardBelongsToLedSuit(Table, _<\/span><\/p>\n

 <\/span>Me<\/span>.CardsHeldThisHand(i)) Then<\/span><\/span><\/p>\n

‘ Wrong suit \u2013 disable the card<\/span><\/span><\/p>\n

                                <\/span>Table.TableTopCards(Seats.Player, _<\/span><\/p>\n

i).Enabled = False<\/span><\/span><\/p>\n

                            <\/span>Else<\/span><\/span><\/p>\n

                                <\/span>AnyValid = True<\/span><\/span><\/p>\n

                            <\/span>End<\/span> If<\/span><\/span><\/p>\n

                        <\/span>End<\/span> If<\/span><\/span><\/p>\n

                    <\/span>Else<\/span><\/span><\/p>\n

                        <\/span><\/span>‘ Disable any labels representing <\/span><\/p>\n

‘ already-played cards.<\/span><\/span><\/p>\n

                        <\/span>Table.TableTopCards(Seats.Player, i).Enabled = False<\/span><\/span><\/p>\n

                    <\/span>End<\/span> If<\/span><\/span><\/p>\n

                <\/span>Next<\/span><\/span><\/p>\n

 <\/span><\/p>\n

                <\/span>If<\/span> AnyValid = False<\/span> Then<\/span> ‘ Nothing of suit \u2013 <\/span><\/span><\/p>\n

‘ can play whatever you want,<\/span><\/p>\n

‘ so re-enable unplayed cards<\/span><\/p>\n

                    <\/span>For<\/span> i = 0 To<\/span> 4<\/span><\/p>\n

                        <\/span>If<\/span> Not<\/span> Me<\/span>.CardsHeldThisHand(i) Is<\/span> Nothing<\/span> Then<\/span><\/span><\/p>\n

                            <\/span>Table.TableTopCards(Seats.Player, _<\/span><\/p>\n

i).Enabled = True<\/span><\/span><\/p>\n

                        <\/span>End<\/span> If<\/span><\/span><\/p>\n

                    <\/span>Next<\/span><\/span><\/p>\n

                <\/span>End<\/span> If<\/span><\/span><\/p>\n

 <\/span><\/p>\n

                <\/span>Table.SelectLabel.Visible = True<\/span><\/span><\/p>\n

                <\/span>Table.SelectLabel.Update()<\/span><\/p>\n

                <\/span>Table.PlayerIsPlayingACard = True<\/span><\/span><\/p>\n

                <\/span>Table.SetPlayerCursorToHand(True<\/span>)<\/span><\/p>\n

 <\/span><\/p>\n

              <\/span>  <\/span>‘ Do a message pump here:<\/span><\/span><\/p>\n

                <\/span>Do<\/span> While<\/span> Table.PlayerIsPlayingACard = True<\/span><\/span><\/p>\n

                    <\/span>My<\/span>.Application.DoEvents()<\/span><\/p>\n

                    <\/span>If<\/span> Table.Exiting = True<\/span> Then<\/span><\/span><\/p>\n

                        <\/span>Dim<\/span> e As<\/span> New<\/span> EuchreException(“ExitGame”<\/span>)<\/span><\/p>\n

                        <\/span>Throw<\/span> e<\/span><\/p>\n

                    <\/span>End<\/span> If<\/span><\/span><\/p>\n

                    <\/span>If<\/span> Table.Restarting = True<\/span> Then<\/span><\/span><\/p>\n

                        <\/span>Dim<\/span> e As<\/span> New<\/span> EuchreException(“NewGame”<\/span>)<\/span><\/p>\n

                        <\/span>Throw<\/span> e<\/span><\/p>\n

                    <\/span>End<\/span> If<\/span><\/span><\/p>\n

                <\/span>Loop<\/span><\/span><\/p>\n

 <\/span>               <\/span>Table.SelectLabel.Visible = False<\/span><\/span><\/p>\n

                <\/span>For<\/span> i = 0 To<\/span> 4<\/span><\/p>\n

                    <\/span>Table.TableTopCards(Seats.Player, i).Enabled = True<\/span><\/span><\/p>\n

                <\/span>Next<\/span> i<\/span><\/p>\n

                <\/span>Table.Update()<\/span><\/p>\n

                <\/span>index = Table.SelectedCard ‘ Get the card the player picked<\/span><\/span><\/p>\n

            <\/span>Else<\/span><\/span><\/p>\n

            <\/span>    <\/span><\/span>‘ Not a human being \u2013 let the AI pick a card<\/span><\/span><\/p>\n

                <\/span>index = AutoPlayACard(Table)<\/span><\/p>\n

            <\/span>End<\/span> If<\/span><\/span><\/p>\n

        <\/span>End<\/span> If<\/span><\/span><\/p>\n

 <\/font><\/p>\n

And then we\u2019d go on to use the value of \u201cindex\u201d to graphically play the selected card, mark it as played, etc.  <\/span>Now, the above relies on the member variable<\/font> PlayerIsPlayingACard<\/span> in order to exit the message pump.  <\/span>So, as you\u2019ve probably guessed, there\u2019s an event handler out there which will change this value whenever the \u201cClick\u201d event happens on a card:   <\/span><\/font><\/font><\/p>\n

    <\/span>Private<\/span> Sub<\/span> PlayerCard_Click(ByVal<\/span> sender As<\/span> System.Object, _<\/span><\/p>\n

ByVal<\/span> e As<\/span> System.EventArgs) _<\/span><\/p>\n

        <\/span>Handles<\/span> PlayerCard1.Click, PlayerCard2.Click, <\/span><\/p>\n

PlayerCard3.Click, PlayerCard4.Click, PlayerCard5.Click<\/span><\/p>\n

        <\/span>If<\/span> PlayerIsDroppingACard = True<\/span> OrElse<\/span> _<\/span><\/p>\n

PlayerIsPlayingACard = True<\/span> Then<\/span><\/span><\/p>\n

            <\/span>If<\/span> sender Is<\/span> PlayerCard1 Then<\/span><\/span><\/p>\n

                <\/span>SelectedCard = 0<\/span><\/p>\n

            <\/span>ElseIf<\/span> sender Is<\/span> PlayerCard2 Then<\/span><\/span><\/p>\n

                <\/span>SelectedCard = 1<\/span><\/p>\n

            <\/span>ElseIf<\/span> sender Is<\/span> PlayerCard3 Then<\/span><\/span><\/p>\n

                <\/span>SelectedCard = 2<\/span><\/p>\n

            <\/span>ElseIf<\/span> sender Is<\/span> PlayerCard4 Then<\/span><\/span><\/p>\n

                <\/span>SelectedCard = 3<\/span><\/p>\n

            <\/span>ElseIf<\/span> sender Is<\/span> PlayerCard5 Then<\/span><\/span><\/p>\n

                <\/span>SelectedCard = 4<\/span><\/p>\n

            <\/span>End<\/span> If<\/span><\/span><\/p>\n

 <\/span><\/p>\n

            <\/span>PlayerIsDroppingACard = False<\/span><\/span><\/p>\n

            <\/span>PlayerIsPlayingACard = False<\/span><\/span><\/p>\n

            <\/span>SetPlayerCursorToHand(False<\/span>)<\/span><\/p>\n

        <\/span>End<\/span> If<\/span><\/span><\/p>\n

    <\/span>End<\/span> Sub<\/span><\/span><\/p>\n

 <\/font><\/p>\n

To create this handler, I just double-clicked on the first player card label on the form to create the handler for that card, typed in the other four labels\u2019 click events to the handles clause in the method signature, and filled in the code.  <\/span>(I also renamed the handler from PlayerCard1_Click to just PlayerCard_Click to indicate to me that it handles all of the player card clicks, but that\u2019s just a cosmetic change and is not essential.)<\/font><\/p>\n

However, in Euchre, sometimes the user feedback needs to be more complicated than simply clicking a card.  <\/span>The user needs to be able to “bid” on trump at the beginning of the round.  <\/span>I\u2019ll need to explain a bit of the rules here to make that clearer: in Euchre, you use a deck of 24 cards (9 through A) and have four players.  <\/span>Each player gets 5 cards, and this leaves 4 remaining.  <\/span>The 4 are referred to as the \u201cKitty,\u201d and the top one is turned up.  <\/span>Each player gets a turn to decide if that want that card\u2019s suit to be trump (i.e., will his or her team capture at least 3 of the 5 hands if that suit is trump).  If the player wants that card’s suit to be trump, the dealer picks it up and discards one of their own cards, meaning that the dealer will have at least one trump card.  <\/span>If nobody wants that card\u2019s suit to be trump, then there is another bidding round where players either pass or select any of the remaining trump suits (in order) until a suit is selected.  <\/span>If everyone passes, then either the deal passes to the next player, or the current dealer is \u201cstuck\u201d selecting trump, depending on the rules you prefer.<\/font><\/p>\n

So, we need a way to let the user bid on the trump.  <\/span>We might be tempted to use a modal dialog here, but if we do, we\u2019re blocking the close and new game events (as well as any ability to reposition the main window while the modal dialog is up).  <\/span>Modeless dialogs won\u2019t be much help, either, since we\u2019d have to set up some sort of messaging between them and the main form.  <\/span>So, what do we do?  <\/span>Well, let\u2019s take a lesson from the \u201cplay a card\u201d scenario.  <\/span>Ideally, we need a bid control which will be enabled when the bidding occurs; otherwise, it should be invisible.  <\/span>We\u2019ll use the most powerful control we\u2019ve got \u2013 the user control.<\/font><\/p>\n

The user control is so powerful because it\u2019s a control that you define yourself.  <\/span>It\u2019s like having a mini-form living inside another form.  <\/span>To create a user control, simply choose \u201cAdd User Control\u201d from the \u201cProject\u201d menu.  <\/span>You\u2019ll get the typical form editor coming up, to which you just add in whatever controls you need.  <\/span>My two bidding user controls are attached to this post, so go ahead & take a look.  <\/font>Either of them is one control as far as the main form is concerned, although internally they\u2019re made up of multiple controls.  <\/span>The user controls show up in the form\u2019s toolbox after building the project using Project\/Build, so I\u2019ll do that, then I\u2019ll drag both controls to the center of the form.  <\/span>To make sure that they don\u2019t trigger any events before they should, I\u2019ll mark them as Enabled = False, and I\u2019ll hide them with \u201cVisible=False.\u201d   <\/span>It\u2019s then a simple thing to enable them in the main application during the bid, as I do here for the smaller one on the first bidding round:<\/font><\/p>\n

            <\/span>Table.BidControl.Visible = True<\/span><\/span><\/p>\n

            <\/span>Table.BidControl.Enabled = True<\/span><\/span><\/p>\n

            <\/span>Table.BidControl.BringToFront()<\/span><\/p>\n

            <\/span>Table.BidControl.Update()<\/span><\/p>\n

            <\/span>‘ Do a message pump here:<\/span><\/span><\/p>\n

            <\/span>Do<\/span> While<\/span> Table.PlayerIsBidding = True<\/span><\/span><\/p>\n

                <\/span>My<\/span>.Application.DoEvents()<\/span><\/p>\n

                <\/span>If<\/span> Table.Exiting = True<\/span> Then<\/span><\/span><\/p>\n

                    <\/span>Dim<\/span> e As<\/span> New<\/span> EuchreException(“ExitGame”<\/span>)<\/span><\/p>\n

                    <\/span>Throw<\/span> e<\/span><\/p>\n

                <\/span>End<\/span> If<\/span><\/span><\/p>\n

                <\/span>If<\/span> Table.Restarting = True<\/span> Then<\/span><\/span><\/p>\n

                    <\/span>Dim<\/span> e As<\/span> New<\/span> EuchreException(“NewGame”<\/span>)<\/span><\/p>\n

                    <\/span>Throw<\/span> e<\/span><\/p>\n

                <\/span>End<\/span> If<\/span><\/span><\/p>\n

            <\/span>Loop<\/span><\/span><\/p>\n

 <\/font><\/p>\n

And when \u201cPlayerIsBidding\u201d changes to False (as we\u2019ll code it to do when the OK button is pressed on the bid control), we\u2019ll simply get the state of the user control and then disable & hide it.  <\/span>The player’s cards are disabled at this point in the game, so we don’t have to worry about handling any errant clicks on them. Thus, no modality is required; we got the user to focus on the job at hand while not inconveniencing them with a locked main window.  <\/font><\/p>\n

That\u2019s not to say that modal windows are \u201cbad\u201d \u2013 it\u2019s just a matter of knowing when to use them for maximum effectiveness.  <\/span>In the completed VBEuchre game which I\u2019ll be attaching in the final post, you\u2019ll note that I use them for issues that would involve data loss, such as ending the game or starting a new one (\u201cAre you sure you want to exit?\u201d), or for cases where the dialog is likely to be up only rarely and briefly (such as the \u201cAbout\u2026\u201d dialog and the “New Game” dialog).<\/font><\/p>\n

In the next part of this series, I\u2019ll be talking about including sound in your application, including text-to-speech.  <\/span>See you then!<\/font><\/p>\n

EuchreBidDialogs.jpg<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Coding a Euchre Game, Part 5: Modality is a crutch It\u2019s really tempting to rely on modal dialogs in a program.  It forces the user to pay attention to what you feel is the most important thing.  However, modal dialogs can also be frustrating to users and you should be careful about when you use […]<\/p>\n","protected":false},"author":258,"featured_media":8818,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[22,195],"tags":[101,165],"class_list":["post-6473","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-matt-gertz","category-visual-basic","tag-matt-gertz","tag-vb2005"],"acf":[],"blog_post_summary":"

Coding a Euchre Game, Part 5: Modality is a crutch It\u2019s really tempting to rely on modal dialogs in a program.  It forces the user to pay attention to what you feel is the most important thing.  However, modal dialogs can also be frustrating to users and you should be careful about when you use […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/posts\/6473","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/users\/258"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/comments?post=6473"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/posts\/6473\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/media\/8818"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/media?parent=6473"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/categories?post=6473"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/vbteam\/wp-json\/wp\/v2\/tags?post=6473"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}