Implement a very basic input control

* Update CHANGELOG to reflect the release of v2.7

* implemented a VERY BASIC input control

Co-authored-by: Fernando Bevilacqua <dovyski@gmail.com>

cvui.h

@@ -1206,6 +1206,9 @@ namespace internal
 	static int gStackCount = -1;
 	static const int gTrackbarMarginX = 14;
 
+	static cv::String gActivatedInput = "";
+	static int gLastInputKeyPressed = -1;
+
 	bool isMouseButton(cvui_mouse_btn_t& theButton, int theQuery);
 	void resetMouseButton(cvui_mouse_btn_t& theButton);
 	void init(const cv::String& theWindowName, int theDelayWaitKey);
@@ -1636,6 +1639,50 @@ namespace internal
 		return aRet;
 	}
 
+	void input(cvui_block_t& theBlock, int theX, int theY, int theWidth, const cv::String& theName, cv::String& theValue, double theFontScale, bool theUpdateLayout) {
+
+		// Draw input text area and text
+		bool selfActivated = (gActivatedInput == theName);
+		cv::Size aTextSize = cv::getTextSize(theValue, cv::FONT_HERSHEY_SIMPLEX, theFontScale, 1, nullptr);
+		int padding = aTextSize.height / 3;
+		cv::Rect aRect(theX, theY, theWidth, aTextSize.height + 1 + padding * 2);
+		render::rect(theBlock, aRect, (selfActivated?0x777777:0xaaaaaa), 0xffffff);
+		cv::Point aPos(theX+padding, theY + aTextSize.height + padding);
+		render::text(theBlock, theValue, aPos, theFontScale, 0x000000);
+
+		// Update the activate status of the input control.
+		int inputStatus = cvui::iarea(theX, theY, aRect.width, aRect.height);
+		if (inputStatus == cvui::CLICK) { // click inside
+			gActivatedInput = theName;
+			selfActivated = true;
+		}else if(selfActivated) { // click outside while self activated
+			int backgroundStatus = cvui::iarea(0, 0, 10000000, 10000000);
+			if (backgroundStatus == cvui::CLICK) {
+				gActivatedInput = "";
+				selfActivated = false;
+			}
+		}
+
+		// Manipulate the string
+		if (selfActivated && internal::gLastInputKeyPressed != -1) {
+			int key = internal::gLastInputKeyPressed;
+			internal::gLastInputKeyPressed = -1;
+			if (key >= 32) {
+				theValue += (char)key;
+			}else if (key == 0x08 && theValue.length()) {
+				theValue = theValue.substr(0, theValue.length() - 1);
+			}
+		}
+
+		// Update the layout flow according to button size
+		// if we were told to update.
+		if (theUpdateLayout) {
+			cv::Size aSize(theWidth, aTextSize.height + padding * 2);
+			updateLayoutFlow(theBlock, aTextSize);
+		}
+
+	}
+
 	bool button(cvui_block_t& theBlock, int theX, int theY, int theWidth, int theHeight, const cv::String& theLabel, bool theUpdateLayout) {
 		// Calculate the space that the label will fill
 		cv::Size aTextSize = getTextSize(theLabel, cv::FONT_HERSHEY_SIMPLEX, 0.4, 1, nullptr);
@@ -2254,6 +2301,11 @@ bool button(cv::Mat& theWhere, int theX, int theY, cv::Mat& theIdle, cv::Mat& th
 	return internal::button(internal::gScreen, theX, theY, theIdle, theOver, theDown, true);
 }
 
+void input(cv::Mat& theWhere, int theX, int theY, int theWidth, const cv::String& theName, cv::String& theValue, double theFontScale = 0.5) {
+	internal::gScreen.where = theWhere;
+	return internal::input(internal::gScreen, theX, theY, theWidth, theName, theValue, theFontScale, true);
+}
+
 void image(cv::Mat& theWhere, int theX, int theY, cv::Mat& theImage) {
 	internal::gScreen.where = theWhere;
 	return internal::image(internal::gScreen, theX, theY, theImage);
@@ -2446,7 +2498,11 @@ void update(const cv::String& theWindowName) {
 	// If we were told to keep track of the keyboard shortcuts, we
 	// proceed to handle opencv event queue.
 	if (internal::gDelayWaitKey > 0) {
-		internal::gLastKeyPressed = cv::waitKey(internal::gDelayWaitKey);
+		if (internal::gActivatedInput != ""){
+			internal::gLastInputKeyPressed = cv::waitKey(internal::gDelayWaitKey);
+		}else{
+			internal::gLastKeyPressed = cv::waitKey(internal::gDelayWaitKey);
+		}
 	}
 
 	if (!internal::blockStackEmpty()) {

example/src/input/CMakeLists.txt

@@ -0,0 +1,19 @@
+find_package( OpenCV REQUIRED )
+include_directories( ${OpenCV_INCLUDE_DIRS} )
+include_directories(../../..)
+
+set(ApplicationName input)
+
+add_executable(${ApplicationName} main.cpp)
+target_link_libraries( ${ApplicationName} ${OpenCV_LIBS} )
+set_property(TARGET ${ApplicationName} PROPERTY CXX_STANDARD 11)
+install(TARGETS ${ApplicationName} DESTINATION bin)
+
+if(ADD_PYTHON_EXAMPLES)
+	add_custom_command(
+        TARGET ${ApplicationName}
+		POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_CURRENT_SOURCE_DIR}/*.py ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}
+	)
+endif()
+

example/src/input/main.cpp

@@ -0,0 +1,52 @@
+/*
+This is a demo application to showcase keyboard shortcuts. 
+Author: Pascal Thomet
+*/
+
+#include <iostream>
+#include <opencv2/core/core.hpp>
+#include <opencv2/highgui/highgui.hpp>
+#include <opencv2/imgproc/imgproc.hpp>
+
+#define CVUI_IMPLEMENTATION
+#include "cvui.h"
+
+#define WINDOW_NAME	"Button shortcut"
+
+int main(int argc, const char *argv[])
+{
+	cv::Mat frame = cv::Mat(cv::Size(650, 150), CV_8UC3);
+
+	// Init cvui and tell it to use a value of 20 for cv::waitKey()
+	// because we want to enable keyboard shortcut for
+	// all components, e.g. button with label "&Quit".
+	// If cvui has a value for waitKey, it will call
+	// waitKey() automatically for us within cvui::update().
+	cvui::init(WINDOW_NAME, 20);
+  cv::String input1_value = "text1";
+  cv::String input2_value = "text2";
+
+	while (true) {
+		frame = cv::Scalar(49, 52, 49);
+
+		cvui::input(frame, 40, 40, 100, "input1", input1_value);
+		cvui::input(frame, 40, 80, 100, "input2", input2_value);
+
+		// Exit the application if the quit button was pressed.
+		// It can be pressed because of a mouse click or because 
+		// the user pressed the "q" key on the keyboard, which is
+		// marked as a shortcut in the button label ("&Quit").
+		if (cvui::button(frame, 300, 100, "&Quit")) {
+			break;
+		}
+
+		// Since cvui::init() received a param regarding waitKey,
+		// there is no need to call cv::waitKey() anymore. cvui::update()
+		// will do it automatically.
+		cvui::update();
+
+		cv::imshow(WINDOW_NAME, frame);
+	}
+
+	return 0;
+}