]> sigrok.org Git - pulseview.git/commitdiff
MathSignal: Implement custom math signal dialog
authorSoeren Apel <redacted>
Sun, 27 Sep 2020 21:18:53 +0000 (23:18 +0200)
committerSoeren Apel <redacted>
Sun, 27 Sep 2020 21:19:29 +0000 (23:19 +0200)
pv/data/mathsignal.cpp
pv/data/mathsignal.hpp
pv/views/trace/mathsignal.cpp
pv/views/trace/mathsignal.hpp

index 2217bffd9543ff22320ef0992d2350482f316d42..f7de2ff29103a0662e1dce62a74cb33a8372203c 100644 (file)
@@ -67,12 +67,18 @@ struct fnc_sample : public exprtk::igeneric_function<T>
                const scalar_t exprtk_sample_num = scalar_t(parameters[1]);
 
                const std::string str_sig_name = to_str(exprtk_sig_name);
-               const double sample_num = std::max(exprtk_sample_num(), (double)0);
+               const double sample_num = exprtk_sample_num();
+
+               if (sample_num < 0)
+                       return 0;
 
                if (!sig_data)
                        sig_data = owner_.signal_from_name(str_sig_name);
 
-               assert(sig_data);
+               if (!sig_data)
+                       // There doesn't actually exist a signal with that name
+                       return 0;
+
                owner_.update_signal_sample(sig_data, current_segment, sample_num);
 
                return T(sig_data->sample_value);
@@ -288,6 +294,8 @@ void MathSignal::reset_generation()
                // TODO Emulate noquote()
                qDebug().nospace() << name() << ": Error cleared";
        }
+
+       generation_chunk_size_ = ChunkLength;
 }
 
 void MathSignal::begin_generation()
@@ -307,6 +315,7 @@ void MathSignal::begin_generation()
        exprtk_unknown_symbol_table_ = new exprtk::symbol_table<double>();
 
        exprtk_symbol_table_ = new exprtk::symbol_table<double>();
+       exprtk_symbol_table_->add_constant("T", 1 / session_.get_samplerate());
        exprtk_symbol_table_->add_function("sample", *fnc_sample_);
        exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
        exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
@@ -347,7 +356,7 @@ void MathSignal::begin_generation()
                        signal_data* sig_data = signal_from_name(unknown);
                        const shared_ptr<SignalBase> signal = (sig_data) ? (sig_data->sb) : nullptr;
                        if (!signal || (!signal->analog_data())) {
-                               set_error(MATH_ERR_INVALID_SIGNAL, QString(tr("%1 isn't a valid analog signal")) \
+                               set_error(MATH_ERR_INVALID_SIGNAL, QString(tr("\"%1\" isn't a valid analog signal")) \
                                        .arg(QString::fromStdString(unknown)));
                        } else
                                sig_data->ref = &(exprtk_unknown_symbol_table_->variable_ref(unknown));
@@ -370,9 +379,11 @@ void MathSignal::begin_generation()
        }
 }
 
-void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
+uint64_t MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
        const int64_t sample_count)
 {
+       uint64_t count = 0;
+
        shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
        shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 
@@ -396,11 +407,20 @@ void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_samp
                double value = exprtk_expression_->value();
                sample_data[i] = value;
                exprtk_current_sample_ += 1;
+               count++;
+
+               // If during the evaluation of the expression it was found that this
+               // math signal itself is being accessed, the chunk size was reduced
+               // to 1, which means we must stop after this sample we just generated
+               if (generation_chunk_size_ == 1)
+                       break;
        }
 
-       segment->append_interleaved_samples(sample_data, sample_count, 1);
+       segment->append_interleaved_samples(sample_data, count, 1);
 
        delete[] sample_data;
+
+       return count;
 }
 
 void MathSignal::generation_proc()
@@ -440,15 +460,13 @@ void MathSignal::generation_proc()
 
                // Process the samples if necessary...
                if (samples_to_process > 0) {
-                       const uint64_t chunk_sample_count = ChunkLength;
-
                        uint64_t processed_samples = 0;
                        do {
                                const uint64_t start_sample = output_sample_count + processed_samples;
-                               const uint64_t sample_count =
-                                       min(samples_to_process - processed_samples,     chunk_sample_count);
+                               uint64_t sample_count =
+                                       min(samples_to_process - processed_samples,     generation_chunk_size_);
 
-                               generate_samples(segment_id, start_sample, sample_count);
+                               sample_count = generate_samples(segment_id, start_sample, sample_count);
                                processed_samples += sample_count;
 
                                // Notify consumers of this signal's data
@@ -477,6 +495,12 @@ void MathSignal::generation_proc()
 
 signal_data* MathSignal::signal_from_name(const std::string& name)
 {
+       // If the expression contains the math signal itself, we must add every sample to
+       // the output segment immediately so that it can be accessed
+       const QString sig_name = QString::fromStdString(name);
+       if (sig_name == this->name())
+               generation_chunk_size_ = 1;
+
        // Look up signal in the map and if it doesn't exist yet, add it for future use
 
        auto element = input_signals_.find(name);
@@ -485,7 +509,6 @@ signal_data* MathSignal::signal_from_name(const std::string& name)
                return &(element->second);
        } else {
                const vector< shared_ptr<SignalBase> > signalbases = session_.signalbases();
-               const QString sig_name = QString::fromStdString(name);
 
                for (const shared_ptr<SignalBase>& sb : signalbases)
                        if (sb->name() == sig_name) {
@@ -504,6 +527,11 @@ signal_data* MathSignal::signal_from_name(const std::string& name)
                        }
        }
 
+       // If we reach this point, no valid signal was found with the supplied name
+       if (error_type_ == MATH_ERR_NONE)
+               set_error(MATH_ERR_INVALID_SIGNAL, QString(tr("\"%1\" isn't a valid analog signal")) \
+                       .arg(QString::fromStdString(name)));
+
        return nullptr;
 }
 
@@ -524,7 +552,11 @@ void MathSignal::update_signal_sample(signal_data* sig_data, uint32_t segment_id
        const shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
 
        sig_data->sample_num = sample_num;
-       sig_data->sample_value = segment->get_sample(sample_num);
+
+       if (sample_num < segment->get_sample_count())
+               sig_data->sample_value = segment->get_sample(sample_num);
+       else
+               sig_data->sample_value = 0;
 
        // We only have a reference if this signal is used as a scalar;
        // if it's used by a function, it's null
index 76427c56e73079a4757d9b468e32b947478bd0a7..e40dbfb3cf61125643d945b2b760846f4069efee 100644 (file)
 #ifndef PULSEVIEW_PV_DATA_MATHSIGNAL_HPP
 #define PULSEVIEW_PV_DATA_MATHSIGNAL_HPP
 
+#define exprtk_disable_rtl_io_file /* Potential security issue, doubt anyone would use those anyway */
+#define exprtk_disable_rtl_vecops  /* Vector ops are rather useless for math channels */
+#define exprtk_disable_caseinsensitivity /* So that we can have both 't' and 'T' */
+
 #include <limits>
 
 #include <QString>
@@ -91,7 +95,7 @@ private:
        void reset_generation();
        virtual void begin_generation();
 
-       void generate_samples(uint32_t segment_id, const uint64_t start_sample,
+       uint64_t generate_samples(uint32_t segment_id, const uint64_t start_sample,
                const int64_t sample_count);
        void generation_proc();
 
@@ -122,6 +126,7 @@ private:
        uint64_t custom_sample_rate_;
        uint64_t custom_sample_count_;
        bool use_custom_sample_rate_, use_custom_sample_count_;
+       uint64_t generation_chunk_size_;
        map<std::string, signal_data> input_signals_;
 
        QString expression_;
index 13dd0665d617ec071d992e5b111b6c89131400fe..2d242b9994da3e3c08d1003099b37d676521ddbb 100644 (file)
 #include <QDialogButtonBox>
 #include <QFormLayout>
 #include <QGridLayout>
+#include <QLabel>
 #include <QLineEdit>
+#include <QPushButton>
 #include <QString>
+#include <QTabWidget>
+#include <QVBoxLayout>
 
 #include "mathsignal.hpp"
 
@@ -39,32 +43,236 @@ namespace trace {
 
 #define MATHSIGNAL_INPUT_TIMEOUT (2000)
 
+const vector< pair<string, string> > MathEditDialog::Examples = {
+       {"Product of signals named A1 and A2:",
+        "A1 * A2"},
+       {"Create a sine wave with f=1MHz:",
+        "sin(1e6 * 2 * pi * t)"},
+       {"Average the past 4 samples of A2:",
+        "var v := 0;\n" \
+        "var n := 4;\n\n" \
+        "for (var i := 0; i < n; i += 1) {\n" \
+        "\tv += sample('A2', s - i) / n;\n" \
+        "}"},
+       {"Create a <a href=https://en.wikipedia.org/wiki/Chirp#Linear>frequency sweep</a> from 1Hz to 1MHz over 10 seconds:",
+        "var f_min := 1;\n" \
+        "var f_max := 1e6;\n" \
+        "var duration := 10;\n" \
+        "var gradient := (f_max - f_min) / duration;\n" \
+        "// phase is the antiderivative of (gradient * t + f_min) dt\n" \
+        "var phase := gradient * (t ^ 2 / 2) + f_min * t;\n" \
+        "sin(2 * pi * phase)"},
+       {"Single-pole low-pass IIR filter, see " \
+        "<a href=https://tomroelandts.com/articles/low-pass-single-pole-iir-filter>this</a> " \
+        "and <a href=https://dsp.stackexchange.com/questions/34969/cutoff-frequency-of-a-first-order-recursive-filter>this</a> article:",
+        "// -3db point is set to 10% of the sampling frequency\n" \
+        "var f_c := 0.1;\n" \
+        "var omega_c := 2 * pi * f_c;\n" \
+        "var b := 2 - cos(omega_c) - sqrt(((2 - cos(omega_c)) ^ 2) - 1);\n" \
+        "var a := 1 - b;\n\n" \
+        "// formula is y[n] = ax[n] + (1 - a) * y[n - 1]\n" \
+        "// x[n] becomes the input signal, here A4\n" \
+        "// y[n - 1] becomes sample('Math1', s - 1)\n" \
+        "a * A4 + (1 - a) * sample('Math1', s - 1)"}
+};
+
 
 MathEditDialog::MathEditDialog(pv::Session &session,
        shared_ptr<pv::data::MathSignal> math_signal, QWidget *parent) :
        QDialog(parent),
        session_(session),
        math_signal_(math_signal),
-       expression_(math_signal->get_expression()),
-       old_expression_(math_signal->get_expression())
+       old_expression_(math_signal->get_expression()),
+       expr_edit_(new QPlainTextEdit())
 {
        setWindowTitle(tr("Math Expression Editor"));
 
+       // Create the pages
+       QWidget *basics_page = new QWidget();
+       QVBoxLayout *basics_layout = new QVBoxLayout(basics_page);
+       basics_layout->addWidget(new QLabel("<b>" + tr("Inputs:") + "</b>"));
+       basics_layout->addWidget(new QLabel("signal_name\tCurrent value of signal signal_name (e.g. A0 or CH1)"));
+       basics_layout->addWidget(new QLabel("T\t\tSampling interval (= 1 / sample rate)"));
+       basics_layout->addWidget(new QLabel("t\t\tCurrent time in seconds"));
+       basics_layout->addWidget(new QLabel("s\t\tCurrent sample number"));
+       basics_layout->addWidget(new QLabel("sample('s', n)\tValue of sample #n of the signal named s"));
+       basics_layout->addWidget(new QLabel("<b>" + tr("Variables:") + "</b>"));
+       basics_layout->addWidget(new QLabel("var x;\t\tCreate variable\nvar x := 5;\tCreate variable with initial value"));
+       basics_layout->addWidget(new QLabel("<b>" + tr("Basic operators:") + "</b>"));
+       basics_layout->addWidget(new QLabel("x + y\t\tAddition of x and y"));
+       basics_layout->addWidget(new QLabel("x - y\t\tSubtraction of x and y"));
+       basics_layout->addWidget(new QLabel("x * y\t\tMultiplication of x and y"));
+       basics_layout->addWidget(new QLabel("x / y\t\tDivision of x and y"));
+       basics_layout->addWidget(new QLabel("x % y\t\tRemainder of division x / y"));
+       basics_layout->addWidget(new QLabel("x ^ y\t\tx to the power of y"));
+       basics_layout->addWidget(new QLabel("<b>" + tr("Assignments:") + "</b>"));
+       basics_layout->addWidget(new QLabel("x := y\t\tAssign the value of y to x"));
+       basics_layout->addWidget(new QLabel("x += y\t\tIncrement x by y"));
+       basics_layout->addWidget(new QLabel("x -= y\t\tDecrement x by y"));
+       basics_layout->addWidget(new QLabel("x *= y\t\tMultiply x by y"));
+       basics_layout->addWidget(new QLabel("x /= y\t\tDivide x by y"));
+       basics_layout->addWidget(new QLabel("x %= y\t\tSet x to the value of x % y"));
+
+       QWidget *func1_page = new QWidget();
+       QVBoxLayout *func1_layout = new QVBoxLayout(func1_page);
+       func1_layout->addWidget(new QLabel("<b>" + tr("General purpose functions:") + "</b>"));
+       func1_layout->addWidget(new QLabel(tr("abs(x)\t\tAbsolute value of x")));
+       func1_layout->addWidget(new QLabel(tr("avg(x, y, ...)\tAverage of all input values")));
+       func1_layout->addWidget(new QLabel(tr("ceil(x)\t\tSmallest integer that is greater than or equal to x")));
+       func1_layout->addWidget(new QLabel(tr("clamp(lb, x, ub)\tClamp x in range between lb and ub, where lb < ub")));
+       func1_layout->addWidget(new QLabel(tr("equal(x, y)\tEquality test between x and y using normalised epsilon")));
+       func1_layout->addWidget(new QLabel(tr("erf(x)\t\tError function of x")));
+       func1_layout->addWidget(new QLabel(tr("erfc(x)\t\tComplimentary error function of x")));
+       func1_layout->addWidget(new QLabel(tr("exp(x)\t\te to the power of x")));
+       func1_layout->addWidget(new QLabel(tr("expm1(x)\te to the power of x minus 1, where x is very small.")));
+       func1_layout->addWidget(new QLabel(tr("floor(x)\t\tLargest integer that is less than or equal to x")));
+       func1_layout->addWidget(new QLabel(tr("frac(x)\t\tFractional portion of x")));
+       func1_layout->addWidget(new QLabel(tr("hypot(x)\t\tHypotenuse of x and y (i.e. sqrt(x*x + y*y))")));
+       func1_layout->addWidget(new QLabel(tr("iclamp(lb, x, ub)\tInverse-clamp x outside of the range lb and ub, where lb < ub.\n\t\tIf x is within the range it will snap to the closest bound")));
+       func1_layout->addWidget(new QLabel(tr("inrange(lb, x, ub)\tIn-range returns true when x is within the range lb and ub, where lb < ub.")));
+       func1_layout->addWidget(new QLabel(tr("log(x)\t\tNatural logarithm of x")));
+       func1_layout->addWidget(new QLabel(tr("log10(x)\t\tBase 10 logarithm of x")));
+
+       QWidget *func2_page = new QWidget();
+       QVBoxLayout *func2_layout = new QVBoxLayout(func2_page);
+       func2_layout->addWidget(new QLabel(tr("log1p(x)\t\tNatural logarithm of 1 + x, where x is very small")));
+       func2_layout->addWidget(new QLabel(tr("log2(x)\t\tBase 2 logarithm of x")));
+       func2_layout->addWidget(new QLabel(tr("logn(x)\t\tBase N logarithm of x, where n is a positive integer")));
+       func2_layout->addWidget(new QLabel(tr("max(x, y, ...)\tLargest value of all the inputs")));
+       func2_layout->addWidget(new QLabel(tr("min(x, y, ...)\tSmallest value of all the inputs")));
+       func2_layout->addWidget(new QLabel(tr("mul(x, y, ...)\tProduct of all the inputs")));
+       func2_layout->addWidget(new QLabel(tr("ncdf(x)\t\tNormal cumulative distribution function")));
+       func2_layout->addWidget(new QLabel(tr("nequal(x, y)\tNot-equal test between x and y using normalised epsilon")));
+       func2_layout->addWidget(new QLabel(tr("pow(x, y)\tx to the power of y")));
+       func2_layout->addWidget(new QLabel(tr("root(x, n)\tNth-Root of x, where n is a positive integer")));
+       func2_layout->addWidget(new QLabel(tr("round(x)\t\tRound x to the nearest integer")));
+       func2_layout->addWidget(new QLabel(tr("roundn(x, n)\tRound x to n decimal places, where n > 0 and is an integer")));
+       func2_layout->addWidget(new QLabel(tr("sgn(x)\t\tSign of x; -1 if x < 0, +1 if x > 0, else zero")));
+       func2_layout->addWidget(new QLabel(tr("sqrt(x)\t\tSquare root of x, where x >= 0")));
+       func2_layout->addWidget(new QLabel(tr("sum(x, y, ..,)\tSum of all the inputs")));
+       func2_layout->addWidget(new QLabel(tr("swap(x, y)\tSwap the values of the variables x and y and return the current value of y")));
+       func2_layout->addWidget(new QLabel(tr("trunc(x)\t\tInteger portion of x")));
+
+       QWidget *trig_page = new QWidget();
+       QVBoxLayout *trig_layout = new QVBoxLayout(trig_page);
+       trig_layout->addWidget(new QLabel("<b>" + tr("Trigonometry functions:") + "</b>"));
+       trig_layout->addWidget(new QLabel(tr("acos(x)\t\tArc cosine of x expressed in radians. Interval [-1,+1]")));
+       trig_layout->addWidget(new QLabel(tr("acosh(x)\t\tInverse hyperbolic cosine of x expressed in radians")));
+       trig_layout->addWidget(new QLabel(tr("asin(x)\t\tArc sine of x expressed in radians. Interval [-1,+1]")));
+       trig_layout->addWidget(new QLabel(tr("asinh(x)\t\tInverse hyperbolic sine of x expressed in radians")));
+       trig_layout->addWidget(new QLabel(tr("atan(x)\t\tArc tangent of x expressed in radians. Interval [-1,+1]")));
+       trig_layout->addWidget(new QLabel(tr("atan2(x, y)\tArc tangent of (x / y) expressed in radians. [-pi,+pi]  ")));
+       trig_layout->addWidget(new QLabel(tr("atanh(x)\t\tInverse hyperbolic tangent of x expressed in radians")));
+       trig_layout->addWidget(new QLabel(tr("cos(x)\t\tCosine of x")));
+       trig_layout->addWidget(new QLabel(tr("cosh(x)\t\tHyperbolic cosine of x")));
+       trig_layout->addWidget(new QLabel(tr("cot(x)\t\tCotangent of x")));
+       trig_layout->addWidget(new QLabel(tr("csc(x)\t\tCosectant of x")));
+       trig_layout->addWidget(new QLabel(tr("sec(x)\t\tSecant of x")));
+       trig_layout->addWidget(new QLabel(tr("sin(x)\t\tSine of x")));
+       trig_layout->addWidget(new QLabel(tr("sinc(x)\t\tSine cardinal of x")));
+       trig_layout->addWidget(new QLabel(tr("sinh(x)\t\tHyperbolic sine of x")));
+       trig_layout->addWidget(new QLabel(tr("tan(x)\t\tTangent of x")));
+       trig_layout->addWidget(new QLabel(tr("tanh(x)\t\tHyperbolic tangent of x")));
+       trig_layout->addWidget(new QLabel(tr("deg2rad(x)\tConvert x from degrees to radians")));
+       trig_layout->addWidget(new QLabel(tr("deg2grad(x)\tConvert x from degrees to gradians")));
+       trig_layout->addWidget(new QLabel(tr("rad2deg(x)\tConvert x from radians to degrees")));
+       trig_layout->addWidget(new QLabel(tr("grad2deg(x)\tConvert x from gradians to degrees")));
+
+       QWidget *logic_page = new QWidget();
+       QVBoxLayout *logic_layout = new QVBoxLayout(logic_page);
+       logic_layout->addWidget(new QLabel("<b>" + tr("Logic operators:") + "</b>"));
+       logic_layout->addWidget(new QLabel("true\t\tTrue state or any value other than zero (typically 1)"));
+       logic_layout->addWidget(new QLabel("false\t\tFalse state, value of exactly zero"));
+       logic_layout->addWidget(new QLabel("x and y\t\tLogical AND, true only if x and y are both true"));
+       logic_layout->addWidget(new QLabel("mand(x, y, z, ...)\tMulti-input logical AND, true only if all inputs are true"));
+       logic_layout->addWidget(new QLabel("x or y\t\tLogical OR, true if either x or y is true"));
+       logic_layout->addWidget(new QLabel("mor(x, y, z, ...)\tMulti-input logical OR, true if at least one of the inputs is true"));
+       logic_layout->addWidget(new QLabel("x nand y\t\tLogical NAND, true only if either x or y is false"));
+       logic_layout->addWidget(new QLabel("x nor y\t\tLogical NOR, true only if the result of x or y is false"));
+       logic_layout->addWidget(new QLabel("not(x)\t\tLogical NOT, negate the logical sense of the input"));
+       logic_layout->addWidget(new QLabel("x xor y\t\tLogical NOR, true only if the logical states of x and y differ"));
+       logic_layout->addWidget(new QLabel("x xnor y\t\tLogical NOR, true only if x and y have the same state"));
+       logic_layout->addWidget(new QLabel("x & y\t\tSame as AND but with left to right expression short circuiting optimisation"));
+       logic_layout->addWidget(new QLabel("x | y\t\tSame as OR but with left to right expression short circuiting optimisation"));
+
+       QWidget *control1_page = new QWidget();
+       QVBoxLayout *control1_layout = new QVBoxLayout(control1_page);
+       control1_layout->addWidget(new QLabel("<b>" + tr("Comparisons:") + "</b>"));
+       control1_layout->addWidget(new QLabel(tr("x = y or x == y\tTrue only if x is strictly equal to y")));
+       control1_layout->addWidget(new QLabel(tr("x <> y or x != y\tTrue only if x does not equal y")));
+       control1_layout->addWidget(new QLabel(tr("x < y\t\tTrue only if x is less than y")));
+       control1_layout->addWidget(new QLabel(tr("x <= y\t\tTrue only if x is less than or equal to y")));
+       control1_layout->addWidget(new QLabel(tr("x > y\t\tTrue only if x is greater than y")));
+       control1_layout->addWidget(new QLabel(tr("x >= y\t\tTrue only if x is greater than or equal to y")));
+       control1_layout->addWidget(new QLabel("<b>" + tr("Flow control:") + "</b>"));
+       control1_layout->addWidget(new QLabel(tr("{ ... }\t\tBeginning and end of instruction block")));
+       control1_layout->addWidget(new QLabel(tr("if (x, y, z)\tIf x is true then return y else return z\nif (x) y;\t\t\tvariant without implied else\nif (x) { y };\t\tvariant with an instruction block\nif (x) y; else z;\t\tvariant with explicit else\nif (x) { y } else { z };\tvariant with instruction blocks")));
+       control1_layout->addWidget(new QLabel(tr("x ? y : z\tTernary operator, equivalent to 'if (x, y, z)'")));
+       control1_layout->addWidget(new QLabel(tr("switch {\t\tThe first true case condition that is encountered will\n case x > 1: a;\tdetermine the result of the switch. If none of the case\n case x < 1: b;\tconditions hold true, the default action is used\n default:     c;\tto determine the return value\n}")));
+
+       QWidget *control2_page = new QWidget();
+       QVBoxLayout *control2_layout = new QVBoxLayout(control2_page);
+       control2_layout->addWidget(new QLabel(tr("while (conditon) {\tEvaluates expression repeatedly as long as condition is true,\n expression;\treturning the last value of expression\n}")));
+       control2_layout->addWidget(new QLabel(tr("repeat\t\tEvalues expression repeatedly as long as condition is false,\n expression;\treturning the last value of expression\nuntil (condition)\n")));
+       control2_layout->addWidget(new QLabel(tr("for (var x := 0; condition; x += 1) {\tRepeatedly evaluates expression while the condition is true,\n expression\t\t\twhile evaluating the 'increment' expression on each loop\n}")));
+       control2_layout->addWidget(new QLabel(tr("break\t\tTerminates the execution of the nearest enclosed loop, returning NaN")));
+       control2_layout->addWidget(new QLabel(tr("break[x]\t\tTerminates the execution of the nearest enclosed loop, returning x")));
+       control2_layout->addWidget(new QLabel(tr("continue\t\tInterrupts loop execution and resumes with the next loop iteration")));
+       control2_layout->addWidget(new QLabel(tr("return[x]\t\tReturns immediately from within the current expression, returning x")));
+       control2_layout->addWidget(new QLabel(tr("~(expr; expr; ...)\tEvaluates each sub-expression and returns the value of the last one\n~{expr; expr; ...}")));
+
+       QWidget *example_page = new QWidget();
+       QVBoxLayout *example_layout = new QVBoxLayout(example_page);
+       for (const pair<string, string> &entry : Examples) {
+               const string &desc = entry.first;
+               const string &example = entry.second;
+
+               QLabel *desc_label = new QLabel("<b>" + tr(desc.c_str()) + "</b>");
+               desc_label->setTextInteractionFlags(Qt::TextSelectableByMouse | Qt::LinksAccessibleByMouse | Qt::LinksAccessibleByKeyboard);
+               desc_label->setOpenExternalLinks(true);
+               example_layout->addWidget(desc_label);
+               QPushButton *btn = new QPushButton(tr("Copy to expression"));
+               connect(btn, &QPushButton::clicked, this, [&]() { set_expr(QString::fromStdString(example)); });
+               QGridLayout *gridlayout = new QGridLayout();
+               gridlayout->addWidget(new QLabel(QString::fromStdString(example)), 0, 0, Qt::AlignLeft);
+               gridlayout->addWidget(btn, 0, 1, Qt::AlignRight);
+               example_layout->addLayout(gridlayout);
+       }
+
        // Create the rest of the dialog
        QDialogButtonBox *button_box = new QDialogButtonBox(
                QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
 
-       QVBoxLayout* root_layout = new QVBoxLayout(this);
-//     root_layout->addLayout(tab_layout);
+       QTabWidget *tabs = new QTabWidget();
+       tabs->addTab(basics_page, tr("Basics"));
+       tabs->addTab(func1_page, tr("Functions 1"));
+       tabs->addTab(func2_page, tr("Functions 2"));
+       tabs->addTab(trig_page, tr("Trigonometry"));
+       tabs->addTab(logic_page, tr("Logic"));
+       tabs->addTab(control1_page, tr("Flow Control 1"));
+       tabs->addTab(control2_page, tr("Flow Control 2"));
+       tabs->addTab(example_page, tr("Examples"));
+
+       QVBoxLayout *root_layout = new QVBoxLayout(this);
+       root_layout->addWidget(tabs);
+       root_layout->addWidget(expr_edit_);
        root_layout->addWidget(button_box);
 
+       // Set tab width to 4 characters
+       expr_edit_->setTabStopWidth(util::text_width(QFontMetrics(font()), "XXXX"));
+
        connect(button_box, SIGNAL(accepted()), this, SLOT(accept()));
        connect(button_box, SIGNAL(rejected()), this, SLOT(reject()));
 }
 
+void MathEditDialog::set_expr(const QString &expr)
+{
+       expr_edit_->document()->setPlainText(expr);
+}
+
 void MathEditDialog::accept()
 {
-       math_signal_->set_expression(expression_);
+       math_signal_->set_expression(expr_edit_->document()->toPlainText());
        QDialog::accept();
 }
 
@@ -139,6 +347,7 @@ void MathSignal::on_sample_count_changed(const QString &text)
 void MathSignal::on_edit_clicked()
 {
        MathEditDialog dlg(session_, math_signal_);
+       dlg.set_expr(expression_edit_->text());
 
        dlg.exec();
 }
index 4b8fcb180e15ddf5a7a9940869596bda8e2e6fda..6af708e502e97e752e9ddeba7f5eacb2ca7bdd59 100644 (file)
 #ifndef PULSEVIEW_PV_VIEWS_TRACE_MATHSIGNAL_HPP
 #define PULSEVIEW_PV_VIEWS_TRACE_MATHSIGNAL_HPP
 
+#include <memory>
+#include <vector>
+
 #include <QComboBox>
 #include <QDialog>
+#include <QPlainTextEdit>
 #include <QString>
 #include <QTimer>
 
 #include <pv/data/mathsignal.hpp>
 #include <pv/views/trace/analogsignal.hpp>
 
+using std::pair;
 using std::shared_ptr;
+using std::string;
+using std::vector;
 
 namespace pv {
 namespace views {
@@ -38,10 +45,15 @@ class MathEditDialog : public QDialog
 {
        Q_OBJECT
 
+private:
+       static const vector< pair<string, string> > Examples;
+
 public:
        MathEditDialog(pv::Session &session, shared_ptr<pv::data::MathSignal> math_signal,
                QWidget *parent = nullptr);
 
+       void set_expr(const QString &expr);
+
 private Q_SLOTS:
        void accept();
        void reject();
@@ -49,7 +61,9 @@ private Q_SLOTS:
 private:
        pv::Session &session_;
        shared_ptr<pv::data::MathSignal> math_signal_;
-       QString expression_, old_expression_;
+       QString old_expression_;
+
+       QPlainTextEdit *expr_edit_;
 };