QT5.8. custom Virtual keyboard including - qt

Question

I'm writing a custom virtual keyboard, which based on QtVirtualKeyboard. For my project I would need to be able to use my version of keyboard.
But the only method, which i found is recompile project and replace original "qtvirtualkeyboardplugin.dll" in "mingw53_32\plugins\platforminputcontexts" on my version of "qtvirtualkeyboardplugin.dll". And use the qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard")); function in main.cpp
After hours of reading the docs and trying various things I'm still cannot find method to use custom keyboard localy, without deleting original "qtvirtualkeyboardplugin.dll".

Answer 1

I'm assuming that you've forked the code, in which case the following modifications seem to be enough to get a differently named plugin to be installed to plugins/platforminputcontexts:
Rename qtvirtualkeyboard/src/virtualkeyboard/qtvirtualkeyboard.json to qtvirtualkeyboard/src/virtualkeyboard/customvirtualkeyboard.json.
In customvirtualkeyboard.json, rename the qtvirtualkeyboard key to customvirtualkeyboard.
In qtvirtualkeyboard/src/virtualkeyboard/plugin.cpp, change the contents of the pluginName string to customvirtualkeyboard.
In qtvirtualkeyboard/src/virtualkeyboard/plugin.h, change the FILE string to customvirtualkeyboard.
In src/virtualkeyboard/virtualkeyboard.pro, change TARGET = qtvirtualkeyboardplugin to TARGET = customvirtualkeyboardplugin. This affects the name of the installed .dll, .lib, etc. that you see in plugins/platforminputcontexts.
Here are the changes as a Git diff:
diff --git a/src/virtualkeyboard/customvirtualkeyboard.json b/src/virtualkeyboard/customvirtualkeyboard.json
new file mode 100644
index 0000000..9ef7a87
--- /dev/null
+++ b/src/virtualkeyboard/customvirtualkeyboard.json
## -0,0 +1,3 ##
+{
+ "Keys": [ "customvirtualkeyboard" ]
+}
diff --git a/src/virtualkeyboard/plugin.cpp b/src/virtualkeyboard/plugin.cpp
index 73ddeab..4abe9a4 100644
--- a/src/virtualkeyboard/plugin.cpp
+++ b/src/virtualkeyboard/plugin.cpp
## -76,7 +76,7 ## using namespace QtVirtualKeyboard;
Q_LOGGING_CATEGORY(qlcVirtualKeyboard, "qt.virtualkeyboard")
-static const char pluginName[] = "qtvirtualkeyboard";
+static const char pluginName[] = "customvirtualkeyboard";
static const char inputMethodEnvVarName[] = "QT_IM_MODULE";
static const char pluginUri[] = "QtQuick.VirtualKeyboard";
static const char pluginSettingsUri[] = "QtQuick.VirtualKeyboard.Settings";
diff --git a/src/virtualkeyboard/plugin.h b/src/virtualkeyboard/plugin.h
index 08074d1..19593a4 100644
--- a/src/virtualkeyboard/plugin.h
+++ b/src/virtualkeyboard/plugin.h
## -38,7 +38,7 ##
class QVirtualKeyboardPlugin : public QPlatformInputContextPlugin
{
Q_OBJECT
- Q_PLUGIN_METADATA(IID QPlatformInputContextFactoryInterface_iid FILE "qtvirtualkeyboard.json")
+ Q_PLUGIN_METADATA(IID QPlatformInputContextFactoryInterface_iid FILE "customvirtualkeyboard.json")
public:
QStringList keys() const;
diff --git a/src/virtualkeyboard/qtvirtualkeyboard.json b/src/virtualkeyboard/qtvirtualkeyboard.json
deleted file mode 100644
index 76d1706..0000000
--- a/src/virtualkeyboard/qtvirtualkeyboard.json
+++ /dev/null
## -1,3 +0,0 ##
-{
- "Keys": [ "qtvirtualkeyboard" ]
-}
diff --git a/src/virtualkeyboard/virtualkeyboard.pro b/src/virtualkeyboard/virtualkeyboard.pro
index 4f3ca69..e9b0ff9 100644
--- a/src/virtualkeyboard/virtualkeyboard.pro
+++ b/src/virtualkeyboard/virtualkeyboard.pro
## -1,4 +1,4 ##
-TARGET = qtvirtualkeyboardplugin
+TARGET = customvirtualkeyboardplugin
DATAPATH = $$[QT_INSTALL_DATA]/qtvirtualkeyboard
QMAKE_DOCS = $$PWD/doc/qtvirtualkeyboard.qdocconf
Remember that if you're using an open source license, you have to make modifications to Qt code available to users of your application.