{"id":3983,"date":"2021-12-26T04:22:03","date_gmt":"2021-12-26T04:22:03","guid":{"rendered":"http:\/\/truelogic.org\/wordpress\/?p=3983"},"modified":"2021-12-26T04:22:04","modified_gmt":"2021-12-26T04:22:04","slug":"6f-wxwidgets-using-window-identifiers","status":"publish","type":"post","link":"https:\/\/truelogic.org\/wordpress\/2021\/12\/26\/6f-wxwidgets-using-window-identifiers\/","title":{"rendered":"6f. wxWidgets – Using Window Identifiers"},"content":{"rendered":"\n

OVERVIEW<\/strong><\/p>\n\n\n\n

Every control or widget that you create is given an id. An id can be system-generated or it can be a predefined system id or you can give it an id of your choice. When you give a widget an id of -1 or wxID_ANY<\/em>, then the system generates an id for that widget. System generated ids are negative eg. -1002, -2019 . <\/p>\n\n\n\n

There are certain ids which are predefined like wxID_EXIT<\/em> or wxID_NEW<\/em>. The functions of these ids are preset in the system so they should not be used for something else than what they are meant to represent.<\/p>\n\n\n\n

You can define your own ids as integer constants. By convention all user-defined ids should start from 101 onwards. You must ensure that all widgets have unique ids otherwise duplicate ids can cause runtime crashes.<\/p>\n\n\n\n

The code below creates three buttons with ids generated in the three ways described above.<\/p>\n\n\n\n

SAMPLE CODE<\/strong><\/p>\n\n\n\n

windows-ids.h<\/pre>\n\n\n
\n#include <wx\/wxprec.h>\n#ifndef WX_PRECOMP\n    #include <wx\/wx.h>\n#endif\n\nclass WindowsIds: public wxFrame {\n\n    public:\n      WindowsIds(const wxString &title);\n      void OnClick(wxCommandEvent &event);\n \n};\nconst int ID_BUTTON =101;\n<\/pre><\/div>\n\n\n
windows-ids-.cpp<\/pre>\n\n\n
\n#include "windows-ids.h"\n\n\nWindowsIds::WindowsIds(const wxString &title):\n\n    wxFrame(NULL, -1, title, wxDefaultPosition, wxSize(500,200)) {\n \n    wxPanel *panel = new wxPanel(this, -1);    \n    wxBoxSizer *hbox = new wxBoxSizer(wxHORIZONTAL);\n    panel->SetSizer(hbox);\n\n    wxButton *btn1 = new wxButton(panel, -1, wxT("Auto Generated Id"));\n    wxButton *btn2 = new wxButton(panel, wxID_EXIT, wxT("System Id"));\n    wxButton *btn3 = new wxButton(panel, ID_BUTTON, wxT("User defined id"));\n   \n    hbox->Add(btn1, 1, wxEXPAND | wxALL, 5);\n    hbox->Add(btn2, 1, wxEXPAND | wxALL, 5);\n    hbox->Add(btn3, 1, wxEXPAND | wxALL, 5);\n\n    btn1->Bind(wxEVT_BUTTON, &WindowsIds::OnClick, this);\n    btn2->Bind(wxEVT_BUTTON, &WindowsIds::OnClick, this);\n    btn3->Bind(wxEVT_BUTTON, &WindowsIds::OnClick, this);\n\n    Center();\n\n}\n\nvoid WindowsIds::OnClick(wxCommandEvent &event) {\n\twxString strId = wxString::Format(wxString("%d"), event.GetId());\n        wxMessageBox(strId);\n\n}\n\n<\/pre><\/div>\n\n\n
main.h<\/pre>\n\n\n
\n#include <wx\/wxprec.h>\n#ifndef WX_PRECOMP\n    #include <wx\/wx.h>\n#endif\n\nclass Main: public wxApp {\n\n\tpublic:\n\t        virtual bool OnInit();\n};\n<\/pre><\/div>\n\n\n
main.cpp<\/pre>\n\n\n
\n#include "main.h"\n#include "windows-ids.h"\n \nIMPLEMENT_APP(Main)\n\nbool Main::OnInit() {\n\n    WindowsIds *app = new WindowsIds(wxT("Windows Ids"));\n    app->Show(true);\n}\n<\/pre><\/div>\n\n\n
The output is shown below<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"
OVERVIEW Every control or widget that you create is given an id. An id can be system-generated or it can be a predefined system id […]<\/a><\/p>\n<\/div>","protected":false},"author":1,"featured_media":3595,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[302,365],"tags":[],"class_list":["post-3983","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cc","category-wxwidgets"],"_links":{"self":[{"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/posts\/3983","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/comments?post=3983"}],"version-history":[{"count":6,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/posts\/3983\/revisions"}],"predecessor-version":[{"id":3993,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/posts\/3983\/revisions\/3993"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/media\/3595"}],"wp:attachment":[{"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/media?parent=3983"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/categories?post=3983"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/truelogic.org\/wordpress\/wp-json\/wp\/v2\/tags?post=3983"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}